Since Thursday more than 20,000 Syrian refugees fleeing their war-torn homeland have arrived in the autonomous Kurdish region of northern Iraq, and more are expected.
"It looks like the total from last Thursday to now is somewhere in the region of 20,000 or more coming across," said Adrian Edwards of the UN refugee agency. "If not the biggest influx across the border at a single time then it is among the largest in the whole Syria crisis."
It's unclear what exactly caused the massive refugee influx, though it's possible fighting between Syrian Kurds and anti-government Islamist militants could be one of many causes.
Some 150,000 Syrians have already entered Iraq, though that's less than most countries, such as Turkey, where many of Syria's 1.9 million refugees are living.