Thousands of Syrian Kurds have poured into Iraq over the past few days, to escape deadly clashes between Kurdish fighters and jihadists.
The UN says more than 15,000 refugees have crossed into Iraq in the latest influx since Thursday, with more expected to follow.
The sudden influx of Syrians across the border stands in marked contrast to the relatively small numbers of refugees taken in by Iraq in recent months compared to other neighbouring countries and has forced the UN refugee agency to scramble aid to the region.
The vast majority of refugees pouring into Iraq's autonomous Kurdish regions in the north are women, children and the elderly.
Several thousand are being housed at the Quru Gusik camp just west of the Kurdish regional capital Arbil, although it is still under construction and lacks many basic services, with others set to be moved to neighbouring Sulaimaniyah province.
But for many, it provides a welcome respite from the fighting ravaging their home districts in a deadly spin-off from the Syrian civil war.
The UN refugee agency UNHCR said on Sunday that the exodus is unlike anything before in Iraq.
"UNHCR is witnessing a major exodus from Syria over the past few days unlike anything we have witnessed entering Iraq previously," Claire Bourgeois, the agency's Iraq representative, said in a statement.
Syrian government forces pulled out of most Kurdish-majority areas of northern and northeastern Syria last year, leaving Kurdish groups to run their own affairs.
But al-Qaeda loyalists, who have played a significant role in the rebellion against President Bashar al-Assad's regime, see the region as a vital link to fellow jihadists in Iraq and have been locked in deadly fighting with Kurdish militias in recent months.
