Isis: Worst refugee crisis in a generation as millions flee Islamic State in Iraq and Syria

The rise of Islamic State (Isis) has displaced over 3.3 million people in Iraq alone, with millions more fleeing Syria for Lebanon, Turkey and the Gulf, and many of them risking perilous journeys to Europe via Egypt, Libya and the Mediterranean.

It was reported in 2015 that asylum applications to rich countries reached their highest level for over two decades in 2014, with 866,000 applications lodged, an increase of 45% on 2013 and two-thirds of those in the European Union.

But while those who have put themselves into the hands of people smugglers and been subjected to horrendous conditions and violence have dominated headlines, the internally displaced within the Middle East face an equally gruelling challenge.

The Kurdish region of Iraq has borne the brunt of the Middle East refugee crisis, accepting as many as one million refugees, who have added one fifth to Iraqi Kurdistan's population. While thousands live in camps set up early in 2014 to accept Syrians feeling the civil war, many others live anywhere they can.

"Many new camps have been built but the vast majority of displaced people are living outside of camps – in houses, construction sites and public spaces," said Tom Robinson, director of Iraqi Kurdistan-based charity Rise Foundation, based in Erbil.

Numbers released by the UN in January estimated the Kurdish Region of Iraq (KRI) is hosting 900,000 refugees, around 233,000 from Syria and the rest from elsewhere in Iraq. As well as Kurds, who have fled northern Syria, the KRI has also accepted thousands of Arabs feeling the cities of Anbar province, which IS recently captured.

Kurdish leaders point out Europe has an obligation to help Iraq solve the refugee crisis given thousands of its young men, by joining IS, have helped create it, but the funding shortfall is severe. "The recent Humanitarian Response Plan launched in Brussels identified a $497m shortfall in funding and is pleading with donors for support," Robinson said.

As well as Iraq, more than 3.8 million Syrians have fled to the neighbouring states of Turkey, Lebanon, Jordan and Egypt and another 7.6 million are displaced inside the country, according to the UN. These include tens of thousands of Palestinian refugees living in the Yarmouk camp near Damascus, which recently became the front line in Syria's civil war.

There, the forces of Syrian dictator Bashar al-Assad fight Islamist militias including IS and Jabhat al-Nusra. The population of the camp is now estimated at around 18,000, with the former residents displaced elsewhere in Syria if they have not been able to fly abroad.

Many Palestinians have taken refuge in Assad-held areas of Syria, while other Palestinian militants have joined the fight against the embattled leader. The UN reported harrowing conditions from the Yarmouk camp earlier in 2015, with the remaining residents effectively living on the front line of a battle between militias and the government.

To the north, refugees have flooded out of Aleppo and other IS-held areas towards Turkey, where reports abound of a huge increase in the number of Syrians begging on the streets of Istanbul and other Turkish cities. Recent days have seen a brief reprieve for some of these refugees after the Kurds re-captured Tel Abyad, allowing them to return home.

The rise of IS has been a major contributor to the profits of the people traffickers in Egypt and Libya, which have reportedly increased tenfold over the past two years. After Eritreans, Syrians are the biggest portion of refugees arriving in Europe and yet a great deal of European nations – Britain included – will only accommodate a fraction of those who reach its shores.

Perversely, as British jihadis flock to Syria to fight alongside IS, Syrians fleeing the terrorist group's brutal rule receive hostility from the majority of Britons, who do not want to see more immigrants – whether refugees or economic migrants – arriving in the country.

Much of the stories of the horrors that refugees have witnessed under IS rule have come from Iraq, where the Yazidi minority suffered harrowing conditions as the terrorist group advanced. Speaking earlier in 2015, UNHCR special envoy Angelina Jolie spoke of the accounts she had heard from those who had escaped or been liberated from IS's grasp.

"Nothing can prepare you for the horrific stories of these survivors of kidnap, abuse and exploitation and to see how they cannot all get the urgent help they need and deserve," Jolie said. "The needs so dramatically outstrip the resources available in this vast crisis. Much more international assistance is needed."

The UN reports that funding shortfalls have made it extremely difficult to cater for increasing numbers of refugees, particularly in the camps that it operates in northern Iraq. UNHCR reported in January that it had received just 53% of the $337m that it needs to cater for displaced Iraqis in the Kurdish region of the country.

Meanwhile, those involved in the aid effort in Iraq expect the refugee crisis will continue as the military defeat in Ramadi makes the liberation of Mosul unlikely in the short term.

Robinson added: "Mosul is not likely going to happen for another year given the political issues and current events taking place throughout Iraq. Coupled with the damage Isis has done to places they inhabited as well as the divisions between ethnicities and religions, many of the displaced are not likely to be going anywhere soon."