Activists have reported violence in several parts of the country on Monday.

The Britain-based Syrian Observatory for Human Rights said 21 civilians, 13 regime troops and four rebels were killed.

Al-Qusayr in the central province of Homs, pounded continuously for three months in a bid by regime forces to wipe out the revolt there, suffered renewed shelling early on Monday.

An AFP correspondent saw several members of one family being treated for wounds, including a 13-year-old boy, after a shell exploded 10 metres away from them. The boy's T-shirt was soaked in blood as his head bled from a deep cut.

"We were on our way to my mother-in-law's house when the bombs began to fall. We tried to run but a bomb exploded right in front of us," said the boy's father, who was also wounded.

Elsewhere, regime forces pressed their campaign against the Khaldiyeh, Jurat al-Shiah and the Old City neighbourhoods of the central city of Homs, the Observatory said.

"Most residents have fled the Old City neighbourhood, and we only get a few hours of electricity a day," an activist who identified himself as Abu Rami told AFP via Skype, adding that the district's infrastructure was "destroyed."

Troops clashed with rebels on the edges of besieged areas, including Sultaniyeh which borders the once rebel-held neighbourhood of Bab Amr, where blasts were also heard.

In the northwestern province of Idlib, regime forces pounded Ariha with shells and heavy machinegun fire, killing at least eight people, the Observatory said. [AFP]