Paris on Tuesday called for a ceasefire, after a monitoring group said at least 45 people were killed by Syrian government airstrikes on the town.
The London-based Syrian Observatory for Human rights said 12 children were among the dead in Tuesday's bombardments
Nearly 200 people have been killed by airstrikes, rocket or artillary fire, since Sunday.
bashar al-Assad's government says the town is being used as a base for rebels to launch rocket attacks on the capital.
State television reported that at least two people were killed and 13 wounded by rebel fire on Damascus earlier today.
French Foreign Affairs Minister Jean-Yves Le Drian warned that "the worst is ahead of us" in Syria on Tuesday.
"The situation in Syria is deteriorating considerably," he told the National Assembly. "It's true so far as I'm concerned that the worst is ahead of us and if nothing changes we are heading for a humanitarian cataclsym."
He repeated France's call for a humanitarian truce.