Two car bombs hit a rebel-held post on the Syrian border with Turkey on Monday, killing at least 16 people and closing the frontier, opposition activists and fighters said.

The Bab al-Hawa crossing is held by a rebel alliance called the Islamic Front, which has been fighting with the Islamic State in Iraq and the Levant (ISIL), a small but powerful affiliate of al Qaeda with a core of foreign fighters.

It was not immediately clear who had planted the bombs. The attack occurred a few days after a car bomb that killed 26 in the eastern city of Jarablus and which activists blamed on ISIL.