Updated

An Al-Qaeda front group fighting in Syria on Wednesday overran the northern town of Azaz near the border with Turkey after fierce clashes with rebels, activists told AFP.

"The Islamic State of Iraq and the Levant (ISIS) has seized complete control of Azaz. They are in control of the town's entrances," said Abu Ahmad, an activist inside the town.

Another activist, a resident of the border town, confirmed the report.

"ISIS are in full control. They are detaining people from their homes, and they are manning all the checkpoints," he told AFP via the Internet, speaking on condition of anonymity.

The development comes amid increasing reports of fighting in northern Syria between ISIS and non-jihadist rebels vying to bring down President Bashar al-Assad's regime.

In a sign that Syria's conflict has grown highly localised in recent months, ISIS has fought side by side with rebels against government troops in other areas of the country.

In Azaz, reports emerged of continuing clashes.

Abu Ahmad said that after seizing the town, ISIS fighters were "on their way to the (nearby) Bab al-Salameh" border crossing with Turkey.

Bab al-Salameh has for months been under control of local rebels, chiefly the Northern Storm brigade.

News of the seizure of Azaz came after a battle lasting several hours between Northern Storm fighters and ISIS.

Among those reported killed in the clashes was Omar Diab, a media activist from Azaz.