US launched missile strikes on Syria in retaliation to Khan Sheikhoun chemical attack - as it happened

Syrian rebels have welcomed the attack but said that Washington's responsibility did not end there and that military strikes should continue to prevent the Syrian government from using airbases and banned weapons.

A statement from the Free Syrian Army - an alliance of rebel groups - said that the strikes were "the correct starting point" for confronting terrorism and finding a "just political situation" to the war.

"We view that the responsibility of the United States is still great, and does not stop with this operation," the statement read.

Why did Trump not need congressional approval before launching the strikes?

Since the War Powers Resolution was enacted in 1973, the US President must consult with Congress before sending armed forces into combat unless there was already a declaration of war. However, this law also gives the president "leeway to respond to attacks or other emergencies," according to the Council on Foreign Relations.

Both Bush and Obama made use of this clause when launching attacks against al-Qaida and Isis. Now Trump has also used the same authority to take military action against Assad's regime.

Turkey's President Tayyip Erdogan described the US strike as a positive development but warned that the attack alone was not enough and that "serious steps" needed to be taken to protect the Syrian people.

"We find it a positive and concrete step taken against the war crimes of the Assad regime. Is it enough? I don't find it enough. It is time to take serious steps for the protection of innocent Syrian people," Erdogan told a rally in the southern province of Hatay in Turkey.

"The international community has the capability to stop the regime and terrorist organisations. I hope the active stance that the United States displayed in Idlib is a beginning with regards to such developments," he said.

Russians were believed to be at the Syrian base hit by the US missile strikes.

Pentagon spokesman Captain Jeff Davis told reporters that Russians were thought to have been at Sharyat Airfield where several Syrian planes were destroyed.

"Russian forces were notified in advance of the strike using the established deconfliction line," Davis said. "US military planners took precautions to minimise risk to Russian or Syrian personnel located at the airfield."

The Kremlin's Foreign Minister Sergey Lavrov said that no Russians were killed in attack. "I hope this provocation will not lead to irreparable damage [to US-Russian ties]," he added.

Assad has said the US strike has increased the Syrian government's resolve to defeat rebel groups and to increase the pace of operations.

"This aggression has increased Syria's resolve to hit those terrorist agents, to continue to crush them, and to raise the pace of action to that end wherever they are," a statement from the president's office read.

The statement added that the US missile strikes were "rash and irresponsible" and that Washington had "naively pulled behind a false propaganda campaign."

The response in Washington to Trump's decision to launch missile strikes against Syria is mixed among both Republicans and Democrats.

Florida Senator Marco Rubio praised the strike as a "tactical action that furthers an objective." He tweeted a passage from the Bible to convey his support for the strike:

Arizona Senator John McCain and South Carolina Senator Lindsay Graham also commended Trump for taking military action.

"Unlike the previous administration, President Trump confronted a pivotal moment in Syria and took action," they said in a joint statement. "For that, he deserves the support of the American people."

Kentucky Senator Paul Rand was more critical of the decision, questioning the strike's legality. "While we all condemn the atrocities in Syria, the United States was not attacked.The President needs Congressional authorization for military action as required by the Constitution," he wrote on Twitter.

Virginia Senator Tim Kaine, who was Hillary Clinton's running-mate in the 2016 election, said that without a vote in Congress the military action was "unconstitutional."

The Khan Sheikhoun chemical strike is the deadliest since the 2013 attack on Ghouta which left more than 1,400 dead.

After the Ghouta attack, President Obama sought Congressional approval for a missile strike against Assad's regime. 183 Republicans were against the strike, with only 12 siding with Obama, according to a whip count by organisation Think Progress.

243 Congressional members voted against military action and Obama pursued a diplomatic response, working together with Putin to pressure Assad into dismantling his chemical weapons programme.The deal removed 1,200 tonnes of chemical weapons from the Syrian battlefield, but was pinpointed by critics as a a weak move that left Assad in control - an argument Trump reignited after the Khan Sheikhoun attack this week:

"President Obama said in 2012 that he would establish a 'red line' against the use of chemical weapons and then did nothing," he commented on 5 April.

After the Ghouta attack, Trump was a vociferous opponent of the US launching a missile strike in retaliation and urged Obama not to attack Syria:

UK Shadow Defence Secretary Nia Griffith backed the US missile strike against Syria, but was overruled by party leader Jeremy Corbyn, a source close to Griffith has confirmed to IBTimes UK.

In statement, Corbyn said the attack risked escalating the conflict.

The Russian Defense Ministry said it would strenghten Syrian air defences in the wake of the missile strikes.

Six fighter jets were destroyed in the US missile strike on a Syrian airfield in Homs province, but the runway remained intact, according to the Russian Ministry of Defense.

The strike destroyed a storage depot, a training facility, a canteen, six MiG-23 aircraft in repair hangars and a radar station.

The runway, taxiways and other aicraft remain undamaged, Russia's Defense Ministry spokesman said in a statement.

The ministry described the combat efficiency of the strike as "quite poor."

"On April 7, 2017, between 3:42am and 3:56am Moscow time, two US Navy destroyers (USS Porter and USS Ross) fired 59 Tomahawk cruise missiles at Shayrat airfield in Homs Province, Syria, from an area near the Island of Crete in the Mediterranean Sea.

"According to our sources, only 23 of them reached the Syrian airbase," Russian Defense Ministry spokesman Major-General Igor Konashenkov said, adding that the points of impact of the other 36 cruise missiles remain unknown.

The ministry said the US actions as "a gross violation" of the memorandum of understanding signed by Moscow in Washington back in 2015 to prevent flight incidents in Syrian airspace.

All justifications for the strike are "groundless claims," the ministry continued.

"Russia made an earlier statement that the Syrian forces did not use chemical weapons. We are waiting for clarification from the US on undisputed – as they claim – evidence that it was the Syrian Army that deployed chemical weapons in the town of Khan Sheikhoun."

It said jihadist groups launched attacks against the Syrian army in the wake of the missile attack.

"A number of measures aimed at strengthening and improving the effectiveness of the Syrian air defence system will be implemented in the near future in order to protect the vital parts of the Syrian infrastructure," Konashenkov said.

Nato Secretary-General Jens Stoltenberg said that Syrian President Bashar al-Assad "bears full responsibility" for the US airstrikes against an air base in Syria, Reuters reports.

"The Syrian regime bears the full responsibility for this development," Stoltenberg said in a statement.

"Any use of chemical weapons is unacceptable, cannot go unanswered, and those responsible must be held accountable," said Stoltenberg, who was informed by the US defence minister that strikes would go ahead.

Labour leader Jeremy Corbyn has broken his silence on the US missile strikes in Syria, saying they risk escalating the conflict.

"The US missile attack on a Syrian government air base risks escalating the war in Syria still further.

"Tuesday's horrific chemical attack was a war crime which requires urgent independent UN investigation and those responsible must be held to account.

"But unilateral military action without legal authorisation or independent verification risks intensifying a multi-sided conflict that has already killed hundreds of thousands of people.

"What is needed instead is to urgently reconvene the Geneva peace talks and unrelenting international pressure for a negotiated settlement of the conflict.

"The terrible suffering of the Syrian people must be brought to an end as soon as possible and every intervention must be judged on what contribution it makes to that outcome.

"The British government should urge restraint on the Trump administration and throw its weight behind peace negotiations and a comprehensive political settlement," said Corbyn.

A World Health Organisation (WHO) spokesman said it was unclear what chemical agenct had been used in Tuesday's attack.

"We don't have confirmation what exactly it was … but it is consistent with toxic symptoms to chemicals," Tarik Jasarevic said at the UN Friday, reported CNN.

He said that around half of the patients taken to Turkish hospitals after the attack appeared to be suffering from the effects of toxic chemicals.

Jasarevic also confirmed that three rescue teams were immediately deployed to the town of Khan Sheikhoun after the attack, where they established contamination tents to triage victims or send them on for further medical assistance.

Syrian state media is reporting that nine civilians, including four children were killed in areas near the airbase in the US missile attack.

Earlier, Syrian officials said that six service personnel were killed in the attack.

Further air strikes have been reported in the town of Khan Sheikhoun, where Wednesday's chemical weapons attack occured.

"A loud explosion was heard in Khan Sheikhounn in the southern countryside of Idlib, where the activists of the Syrian Observatory for Human Rights observed a warplane," reported the UK-based organisation.

It added that the missile from the plane hit an area near the town's north road, and there were no reports on casualties. It said it was unclear if the aircraft was a Syrian regime plane or was part of the Russian military.

A survivor of the 2013 sarin gas attack in Ghouta has praised Trump for ordering the missile attack.

At least 281 were killed in the attack, which brought the US to the brink of millitary attacks on the Assad regime.

European Council President Donald Tusk said the US missile strike showed the West's resolve against chemical attacks.

"U.S. strikes show needed resolve against barbaric chemical attacks. EU will work with the U.S. to end brutality in Syria," Tusk said on Twitter.

Syrian rebel groups have welcomed the missile strikes, AFP has reported.

"Hitting one airbase is not enough, there are 26 airbases that target civilians," a key figure in the Army of Islam faction, Mohamed Alloush, said on his Twitter account.

"The whole world should save the Syrian people from the clutches of the killer Bashar (al-Assad) and his aides."

Other rebel groups welcomed the US strike and called for continued military action against the regime.

"The American strike against the killing tools used by Bashar al-Assad is the first step on the correct path to combating terrorism and we hope it will continue," said Issam Raes, spokesman for the Southern Front rebel faction.

"In my opinion, the message is political, and the message has arrived to Russia and been understood," he told AFP.

Colonel Ahmed Osman, of the Turkey-backed Sultan Murad rebel group said: "We welcome any action that will put an end to the regime that is committing the worst crimes in history."

Mohamed Bayrakdar, another leader of the Army of Islam, which operates mainly around the capital Damascus, described the strike as "a bold and correct step."

"We welcome any response to the crimes of the regime," he told AFP.

Russian Foreign Minister Sergei Lavrov said he hoped the US strikes would not irreperably damage ties between Russia and the US.

"This is an act of aggression, on an absolutely made-up pretext," Lavrov told a news conference in Tashkent, Uzbekistan, as quoted by Reuters. "It reminds me of the situation in 2003 when the United States and Britain, along with some of their allies, attacked Iraq."

He said Russia would demand Washington explain why it conducted the strikes.

"I hope this provocation will not lead to irreparable damage (to US-Russian ties)," Lavrov said.

He added that no Russian service personnel were killed in the attack.

Italy has joined the list of countries backing the US strikes.

Angelino Alfano, the Italian foreign minister, said in a statement that Italy understood the reasons behind US military action and called the strikes a "proportionate" deterrent to the further use of chemical weapons by the Assad regime.

Alfano called for a "necessary and urgent" meeting of the UN Security Council, where Italy, a non-permanent member, has a vote.

The UK hard left Stop the Coaliton, whose former chairman is Labour leader Jeremy Corbyn, is to hold a protest against the missile strikes outside Downing Street tonight.

The group has drawn criticism in the past for not protesting against alleged atrocities by the Assad government and Russian forces in Syria.

Corbyn is yet to release a statement on last night's attack.

Lib Dem leader Tim Farron has expressed his support for the attack.

"The attack by American forces was a proportionate response to the barbarous attack by the Syrian government on its own people.

"The British government rather than just putting out a bland statement welcoming this should now follow it up and call an emergency meeting of the Nato alliance to see what else can be done, be that more surgical strikes or no fly zones.

"Evil happens when good people do nothing, we cannot sit by while a dictator gasses his own people. We cannot stand by, we must act."

Trump's decision is reportedly proving popular across the Arab world.

Here is an overhead view of Shayrat airbase in Homs province, hit in last night's missile strike.

Hours before the attack, Trump's Democrat rival in last year's presidential election, Hilary Clinton, had called for the US to "take out" Assad's air fields.

"Assad has an air force, and that air force is the cause of most of these civilian deaths as we have seen over the years and as we saw again in the last few days," Clinton said in a speech at the "Women in the World" summit in New York City. "And I really believe that we should have and still should take out his air fields and prevent him from being able to use them to bomb innocent people and drop sarin gas on them."

On the campaign trail, Trump had claimed that Clinton's Syria policy risked sparking World War III

The death toll from the missile strike has increased, with a Syrian official telling AP that seven were killed and nine were wounded in the attack.

Prominent figures from the white nationalist 'alt-right' and European populist right have turned on Trump for ordering the missile strike. Previously they lauded the US president for his ati-Nato rhetoric and opposition to western military interventions.

Former Nato Secretary General Anders Rasmussen has backed the missile strike.

Russia has suspended an agreement that prevents direct conflict with US forces.

The Russian Foreign Ministry said in a statement that it was suspending a meomorandum, signed after Russia launched airstrikes in Syria in September 2015, designed to stop mid-air collisions and other incidents between Russian and US aircraft.

Under the agreement, Russia and the US had exchanged information about their flights to avoid incidents in the crowded skies over Syria — where Russia has several dozen warplanes and batteries of air-defense missiles.

German Chancellor Angela Merkel and French President Francois Hollande have released a joint statement in support of the US strikes.

It says: "The president and the German chancellor held talks on the telephone this morning on the situation in Syria.

"Following the chemical massacre on April 4 in Khan Sheikhun in the northwest of Syria, a military installation of the Syrian regime used chemical bombing was destroyed last night by US strikes. We have been informed.

"Assad bears full responsibility for this development. Its continued use of chemical weapons and mass crimes can not go unpunished …

"France and Germany therefore continue their efforts with partners in the United Nations framework to sanction the most appropriate criminal acts related to the use of chemical weapons banned by all treaties.

"We call on the international community to come together for a political transition in Syria, in accordance with resolution 2254 of the security council and the Geneva communiqué."

Russian state-owned news organisation RT has released pictures of the Syrian airbase base hit by the Tomahawk cruise missiles, which show aircraft hangars blackened by smoke.

It reports that nine Syrian jets were destroyed in the attack.

The UK, Israel, Turkey, Saudi Arabia, Japan and New Zealand have all backed the missile strikes.

"Our reaction is we fully support what the Americans have done. It's limited; it's wholly appropriate," UK Defence Secretary Michael Fallon told the BBC's Today programme.

He said the US had not "declared war" on Syria. "The Americans have made it clear the attack last night was limited," he said.

China, which has previously blocked UN resolutions against Assad, has issued an official response to the missile strikes.

Speaking at a press conference in Beijing, the foreign ministry spokesperson Hua Chunying stopped short of explicitly condemning the US air strikes but said China had always been opposed to the "use of force".

Hua said China also opposed "the use of chemical weapons by any country, organisation or individual, in any circumstance and for any purpose".

Provocative state owned Chinese tabloid Global Times condemned the aistrikes, saying Trump ordered the attack to "set up his authority," adding the "haste and inconsistency" of this move has left "a deep impression."

"Trump quickly decided to fight against the Assad regime to set up his authority as the US president," the editorial says. "He wanted to prove that he dares to do what Obama did not dare. While Obama was equivocal, his attitude is clear-cut.

"He also proves to the world that he isn't merely a 'businessman president.' He will mobilize US military force without any hesitation when necessary."

Donald Trump is to meet Chinese President Xi JInping at the US president's Mar-a-Lago resort in Florida.