Syrian government forces have started an intensified military operation against a militant-held enclave near Homs amid a push to regain control over all the remaining areas under their siege.

The so-called Syrian Observatory for Human Rights said on Monday that the operation on the pocket between Homs and Hama included both air raids and artillery.

The observatory said reinforcements had been deployed to government-held areas before the assault, which targeted Rastan, the biggest town in the pocket, and several neighboring villages.

Syrian state television aired footage of efforts underway to clear roads into parts of a pocket in south Damascus where fighting had raged in order to allow militants there to withdraw under a deal.

Takfiri militants have lost much of the territory they once held in Syria amid sweeping gains by government forces on the ground.

Earlier this month, Syrian forces managed to retake the Eastern Ghouta and Eastern Qalamoun regions near the capital.

For years, the areas had served as a launch pad for deadly terror attacks against civilians in Damascus.