At least 10 civilians and three rebels were killed on Thursday in violence across Syria, while car bombs exploded in Damascus and the northwest city of Idlib, monitors reported.
A suicide bomber detonated an explosives-packed vehicle in a suburb of the capital, wounding 14 people and damaging one of Shiite Islam's holiest shrines, state media and witnesses reported.
The state news agency SANA said the vehicle exploded in a garage 50 metres (yards) from the Sayyida Zeinab shrine. There was "substantial damage in the area of the blast," and "the terrorist who carried out the operation was killed."
The car bomb in Idlib city targeted a military checkpoint, the Syrian Observatory for Human Rights said, adding that a number of soldiers were killed or wounded in the blast. No further details were immediately available.
Five civilians were killed during clashes between regime troops and rebels in the central city of Homs, it said, while also reporting renewed regime shelling of Rastan in the province of the same name and of Daraa in southern Syria.
Two opposition fighters, including Ahmed Bahbouh, head of the rebel military office in Rastan and a leading dissident figure, were killed at the entrances of rebel-held Rastan which the regime has been trying to overrun for months.
Another dissident was killed in Homs province.
In the city of Daraa, five people were killed before dawn in the neighbourhood of Tareek al-Sad, which was heavily shelled by regime troops, according to the Britain-based Observatory.
"Government forces have surrounded the neighbourhood of Tareek al-Sad in preparation to storm the area," it said.
At least 77 people were killed across Syria on Wednesday, including 49 civilians, 21 soldiers and seven rebels, the watchdog said.
Over 14,400 people have been killed in the 15-month revolt in Syria, the majority of them civilians, according to the Observatory.
The escalation in violence follows an assessment by UN peacekeeping chief Herve Ladsous on Tuesday that Syria was now locked in fullscale civil war, with regime forces having lost control of "large chunks of territory."