Twelve Syrians, including five children, were killed on Friday when a rocket hit among protesters in the city of Rastan in the central province of Homs, a watchdog said.
The Syrian Observatory for Human Rights said a rocket struck in the middle of a demonstration as the mostly rebel-held city was subjected to shelling and heavy gunfire by forces loyal to President Bashar al-Assad.
Meanwhile, a convoy of seven trucks from the International Committee of the Red Cross and the Syrian Arab Red Crescent is preparing to enter the Baba Amr neighbourhood of Homs, an ICRC spokesman said.
"We are preparing to enter the district of Baba Amr," deputy ICRC spokesman Sebastien Carliez said. "The convoy arrived in Homs a few minutes ago."
The trucks are carrying food, medicines, blankets, baby milk and other equipment to the area, which was overrun by regime forces after a nearly four-week pounding.
The ICRC said Thursday it had received "positive signals" from the Syrian authorities over its request for a daily two-hour humanitarian truce.
The UN Security Council also on Thursday asked the Syrian authorities "to allow free access, full and immediate humanitarian personnel to all people who need help".