Syrian rebels ousted an al Qaeda-linked faction from one of its northwestern bastions on Friday, activists said, a significant blow to the group after two weeks of infighting that has undercut the insurgency against President Bashar al-Assad.

Rebels from Islamists to relatively secular moderates have been fighting the Islamic State of Iraq and the Levant (ISIL) faction in the worst internecine violence to break out since Syria’s conflict began in 2011.

The fighting since the start of January has killed over 1,000 people, according to Syrian Observatory for Human Rights monitors, and helped Assad’s forces claw back territory around the northern commercial hub of Aleppo. […]