Fighting continued in Syria's Idlib province on Tuesday (October 11th) between Islamist rebel groups and extremist group Jund al-Aqsa, a day after the two sides signed a non-aggression pact , AFP reported.

Since October 6th, Jund al-Aqsa has been involved in heavy fighting with opposition groups, including Ahrar al-Sham, in north-western Idlib.

The two groups were once allies in the fight against the regime, though opposition factions have often accused Jund al-Aqsa of ties with the "Islamic State of Iraq and the Levant" (ISIL), which has targeted opposition fighters.

In a bid to calm the tensions, former al-Qaeda affiliate Fatah al-Sham Front -- an ally of Ahrar al-Sham and key rival of ISIL -- announced Sunday it would bring Jund al-Aqsa into its ranks.

On Monday night, Fatah al-Sham and Ahrar al-Sham signed a deal intended to end the in-fighting.

But the Syrian Observatory for Human Rights said the clashes were continuing in Idlib on Tuesday.

Regime forces have taken advantage of the in-fighting to recapture a series of towns and villages in neighbouring Hama province, the Observatory said.