Syrian forces loyal to President Bashar al-Assad shelled the battered city of Homs on Saturday, opposition activists said, the first bombings since a ceasefire began on two days ago.
The United Nations Security Council is tentatively scheduled to vote on a Western-Arab draft resolution authorising an advance UN team to monitor the fragile ceasefire which aims to end 13 months of bloodshed during the uprising against Assad.
It is still unclear if Russia, one of Assad's allies, can be persuaded to support the draft, which calls on Syria to allow access for a team of up to 30 unarmed military observers and threatens to consider "further steps" if Syria does not comply.
"There was shelling last night in the old part of the city, in Jouret al-Shiyah and al-Qaradis. And I have heard eight shells fall in the past hour," Karm Abu Rabea, a resident activist who lives in an adjacent neighbourhood, said on Saturday morning.
The British-based Syrian Observatory for Human Rights and other activists in Homs said shelling had wounded several people overnight. Activist Walid al-Fares showed Reuters footage of a thick pillar of smoke rising next to a mosque minaret. The crack of gunfire can also be heard.
The Syrian government has repeatedly denied access to journalists, making it impossible to independently verify the reports.
Syrians took to the streets across the country in small demonstrations on Friday, trusting the truce would put an end to the bullets that have frightened off peaceful protesters for months.
But Syrian forces loyal to Assad shot dead five protesters after Friday prayers, activists reported, adding that security forces came out in strength in many cities to prevent protesters mounting major rallies against Assad.
Syria's state news agency SANA said "armed terrorists" killed six people on Friday, including army Major Musa al-Yousef in the central city of Hama, who was killed when "terrorists opened fire on a car Yousef was driving to his (army) unit."
Another group of assailants threw a stick of dynamite at an army patrol in the same city, SANA said, and a bomb exploded at a major roundabout.
Bombs were detonated in two areas of Syria's second city of Aleppo on Friday and a member of the security forces was killed in Damascus, SANA said.
"The main roads in some villages have seen a proliferation of armed men, especially in the towns," it added.
The United Nations estimates that Assad's forces have killed more than 9,000 people since the uprising began. Authorities blame the violence on foreign-backed militants who they say have killed more than 2,500 soldiers and police.
International pressure has grown for Syria to fulfil all its commitments to peace envoy Kofi Annan by withdrawing troops and heavy weapons, permitting humanitarian and media access, releasing prisoners and discussing a political transition.
US and European UN delegations had to revise the draft resolution late on Friday after Russia's UN ambassador, Vitaly Churkin, told reporters it needed cutting out "all the things which are not really necessary for this particular purpose."
In the revised draft, wording has been changed and weakened slightly, in some cases from "demands" to "calls upon" or "requests."
The council will reconvene on Saturday at 11 am EDT (1500 GMT).
UN diplomats say Russia supports Annan's peace efforts but is working hard to shield Damascus from what it fears is a Western push for Libyan-style "regime change" to dislodge Moscow from its only geostrategic foothold in the Middle East.
Russia and China have vetoed two resolutions condemning Assad's assault on anti-government protesters.