Syrian rebel fighters loyal to Al-Qaeda ceded ground near the Turkish border to rival rebel groups, activists have said, in what seemed to be a tactical withdrawal to end clashes between those opposed to the regime of President Bashar al-Assad.

Opposition activists said the Islamic State of Iraq and the Levant (ISIL), allied to Al-Qaeda and featuring foreigners among its commanders, had pulled back on Sunday from strong points including al-Dana and Atma in Idlib province and that fighters from Jabhat al-Nusra and Ahrar al-Sham moved in.

Meanwhile, other fighters opposed to the rule of Assad seized a compound garrisoned by ISIL in Aleppo province, in some of the most serious infighting within the rebel groups trying to topple the government, activists said.

The clashes between a loose alliance of opposition brigades and the ISIL, which has sought to impose a strict interpretation of Islam on opposition-held areas, have spread across northern Syria in the last few days.

ISIL, which has many foreign fighters in its ranks, has clashed repeatedly with more moderate rebel groups since it aggressively pushed into Syria from neighboring Iraq last spring.