As many as a million people are expected to flee the Iraqi region of Mosul in the next few months as Iraqi troops prepare to wrestle the territory away from Islamic State. Thousands have already fled and are seeking refuge in Kurdish held areas, further exacerbating the refugee crisis in the Middle East and beyond.

2015 was characterised by the flow of Syrian migrants northwards into Europe, as European leaders sought to exploit the Syrian situation to argue for free passage for all migrants, regardless of provinence.

But the new cause this year could be Iraqi refugees, as moves by the Iraqi authorities to reclaim territory gained by Islamic State is causing potentially millions to flee northwards from Mosul, the largest city within Islamic State, and its surrounding areas.

Nearly 2,000 people have already left the area around Mosul, where Iraqi soldiers have so far captured a handful of villages. When Mosul itself is targeted, the trickle of people is expected to turn into a flood.

“As we look at the likely scenario facing us in the coming months, we know we don’t have the capacity or the funding to deal with this. We are deeply worried,” Lise Grande, the UN’s humanitarian coordinator for Iraq told the Sunday Times.

“If the destruction is extensive, people who have been displaced won’t be able to return to their homes for months, if not longer.”

Iraqi troops are currently headed westwards towards the Islamic State held town of Qayyarah in an offensive which the UN estimates will prompt 100,000 people to flee. When the troops turn north to Mosul, the UN expects as many as a million people, two thirds of Mosul’s population, to be displaced.

Most of the refugees who have already left have travelled north-east to the Kurdish town of Makhmour at the border of the autonomous Kurdistan Region of northern Iraq. Those yet to come are expected to join them.

Kurdistan Region itself already shelters a million Iraqi refugees from elsewhere in the country, as well as a quarter of a million Syria refugees. With the local population numbering just 4.5 million, the refugee count now totals some 30 percent of the local population – the highest ratio in the world.

But with the local government already short of money and fearing security issues associated with opening its doors to people from within Islamic State held territory, it has begun to close its doors to newcomers.

It is allowing them to enter disputed areas such as Makhmour, which lies outside the Region’s official borders and where the UN is currently considering whether to build a new camp.

But security protocols are tight, slowing down the rate at which people can be accepted. Civilians are routinely screened and interrogated with the focus on the men, explained Brigadier Mahdi Younes, the commander of the local Peshmerga forces.

Mother of two Sara Omar, 26, says her husband was taken away by the security forces upon arrival. “They took him away because they suspect him of having links to Isil [Islamic State],” she said.

Another Peshmerga soldier confirmed that Islamic State members and sympathisers were among the civilians. “We found a doctor who was Isil,” he said.

Hours later, a suicide bomber from an Islamic State area penetrated the Peshmerga front line and targeted the police headquarters in Makhmour. Three police officers were killed in the attack.