Syria agreed to the terms of a cease-fire brokered by former U.N. Secretary-General Kofi Annan. A truce was to enter into force April 10.
The Local Coordination Committees in Syria, an umbrella organization in the country, reported Tuesday that "regime forces" used heavy gunfire in the city of Homs and stationed checkpoints around the Baba Amr neighborhood.
Damascus, through the official Syrian Arab News Agency, announced it formed a committee tasked with assessing the damages in Homs and "restore life back to normal."
Iranian Foreign Minister Ali Akbar Salehi said that, despite international efforts, the situation called for a Syrian-led solution.
"The issue of Syria, which has been located in a sensitive region, should be resolved with insight and by the Syrians," he was quoted by state-funded broadcaster Press TV as saying. "Arming the opposition of the Syrian government is not in the interests of the region and will create a vacuum and subsequent insecurity in the region."
Lebanese and Turkish officials have expressed concern the 13-month conflict in Syria could spill over its borders.
Washington and its international allies have said they would support Syrian opposition groups through non-military means.