The Syrian army has killed at least 17 people, including women, during fighting in the southern restive town of Deraa, activists say.
They say the shelling began late on Friday and continued overnight.
There have been frequent clashes between troops and rebels in Deraa, where the uprising against President Bashar al-Assad began last year.
Meanwhile UN monitors continue their investigation into an alleged massacre at Qubair, after visiting the site.
People in the area told the UN team that everyone in the village near Hama "had died except for a few", UN spokeswoman Sausan Ghosheh told the BBC.
She said that the monitors had not yet been able to establish the number of victims. Activists say about 80 people were killed.
The BBC's Paul Danahar, who accompanied the observers to the village on Friday, said the smell of burnt flesh still hung heavy on the air.
Activists said government forces had removed many of the bodies. It is unclear what happened to those of dozens of reported victims.
The opposition blamed the Qubair massacre on militias allied to President Assad while the government accused "terrorists" of killing civilians.
Condemning Wednesday's massacre earlier, UN Secretary General Ban Ki-moon warned of an imminent danger of civil war. International peace envoy, Kofi Annan, has said his six-point peace plan is not being implemented.
The shelling at Deraa, in the far south near the Jordanian border, began shortly after night-time prayers on Friday, according to activists.
They described the bombardment as "hysterical", and said it was mainly focused on a western district.
The UK-based Syrian Observatory for Human rights says most of those killed were women.
Despite frequent attempts to subdue Deraa, the city has never really been completely tamed by government forces and the rebel Free Syrian Army is active in and around the city, says the BBC's Jim Muir in neighbouring Lebanon.
The Observatory says 44 civilians were killed by security forces across Syria on Friday - more than half of them in Damascus districts and in Homs province.
It also says about 25 soldiers were killed in five provinces.
The UN says at least 9,000 people have died since pro-democracy protests began in March 2011.
The Syrian government has signed Mr Annan's six-point peace plan, but says it is fighting foreign-backed rebels.