Syrian troops shelled two central districts of the battered city of Homs throughout the night, al Jazeera television reported on Saturday, citing activists.
Several people were wounded in the first bombings since a fragile UN-Arab League-brokered ceasefire took hold on Thursday, the British-based Syrian Observatory for Human Rights said.
It comes after at least seven people were killed across the country on Friday as police used tear gas and live bullets to disperse fresh protests against President Bashar al-Assad.
Both sides have accused the other of violating the ceasefire.
The UN Security Council is expected to hold a vote later on Saturday on a new resolution authorizing the deployment of UN observers to monitor the truce.
The United States-proposed resolution, backed by Britain, France, Germany, and others, demands "full, unimpeded, and immediate freedom of movement" for the 30-strong mission.
It also warns of "further measures" if the Damascus government fails to "implement visibly" the commitments made under a peace plan proposed by UN special envoy Kofi Annan.
