Taliban parliament attack
A vehicle is seen on fire after a blast near the Afghan parliament in Kabul Reuters

The Afghan capital Kabul has been hit by a series of explosions, including a suicide bombing outside a police academy.

At least 20 people were killed and 25 others injured after the attacker dressed in a police uniform walked up to a group of recruits and detonated his vest which was laden with explosives.

The latest explosion comes just hours after a car bomb killed at least 15 people near a government complex and military base in a residential area.

240 people including women and children were wounded, flooding a nearby hospital with casualties.

Witnesses reported a third blast in central Kabul, striking close to the airport, followed by the sound of gunfire.

A fourth blast was reported targeting an area close to coalition bases and Afghan government buildings.

The assaults undermined claims by security services and the government that the capital was immune from devastating attacks.

More about Kabul bombings

Mr Ghani said he would respond to the attacks with "force and power" but also said he was determined to continue efforts to bring peace to the country.

No one has yet claimed responsibility for the attacks, though security officials indicated that the Taliban is behind the bombings.

It is the first major attack in Kabul since the Taliban announced the death of its former leader Mullah Omar, leader of the Taliban.

The appointment of Mullah Omar's deputy, Mullah Akhtar Mansoor, to succeed him sparked protests from his brother and son.

Mansour pledged to continue the group's 13-year insurgency in his first public message.

Meanwhile, the government said the attacks were aimed at diverting public attention from the group's leadership struggles.

Earlier this week, the UN said civilian casualties in Afghanistan were at a record high of 4,921 in the first six months of 2015, a 1% increase from the same period last year.