BEIRUT, Lebanon — Islamic State militants attacked a checkpoint on Tuesday used by refugees fleeing fighting in Syria and Iraq, killing more than three dozen people, according to local Kurdish militants and monitoring groups.

It was one of the largest recent attacks in the area, Hasaka Province in northeastern Syria, by the Islamic State, which has been under pressure in its main urban centers of Mosul in Iraq and Raqqa in Syria.

The attack took place near Al Hol refugee camp, which hosts nearly 17,000 people, most of them Iraqi refugees but also including displaced Syrians, according to the International Rescue Committee. The group said several children were among the dead and injured.

The battle began with an Islamic State assault on a checkpoint controlled by the Syrian Democratic Forces, a mostly Kurdish force that works with the United States against Islamic State militants, according to Kurdish militia representatives, who said attackers had also targeted civilians in a temporary camp for the displaced.