Two car bombs killed at least six people and wounded several others in Syria's sprawling Rukban refugee camp near the border with Jordan late on Monday, Reuters reported.
One explosion was near a restaurant and the second targeted the camp's market nearby, they said.
"There are at least six civilians dead and the number is expected to rise," said Mohammad Adnan, a rebel official from Jaish Ahrar al-Ashair who runs the policing of the camp.
There was no immediate claim of responsibility.
In January, a car bomb killed a number of people in the camp, and Islamic State militants have since launched attacks on Syrian rebels in the area.
Rukban, near the joint Syria-Iraq-Jordan border, is home to refugees and also to rebel groups, including the Jaish Ahrar al-Ashair, which fight both President Bashar al-Assad and the Islamic State movement. It was also hit by bomb attacks last year.