The United Nations refugee agency says it is scrambling to get aid into northern Iraq after thousands of Syrians crossed the tightly-controlled border in a sudden and unexplained influx.
The vast majority of the new arrivals are women, children and elderly people from the embattled city of Aleppo in northwestern Syria or from communities in the northeast, closer to Iraq.
A United Nations spokesperson says 750 people initially crossed the Tigris River into Iraqi Kurdistan on Thursday, followed by a huge crowd of between 5000 and 7000.
UNHCR and other aid agencies, along with local authorities, have rushed food and water to the site and are working around the clock to build a camp away from the border zone for the new arrivals, Reuters reports.
In total, more than 1.9 million Syrians have fled their homeland's civil war, with most seeking a haven in Lebanon, Jordan and Turkey.
Meanwhile, the UN says its mission to investigate the alleged use of chemical weapons in Syria tentatively plans to enter the country this weekend.