BEIRUT (AP) -- The U.N. Security Council on Saturday approved the deployment of a first team of observers to Syria to shore up a brittle truce, even as a new surge of violence threatened the internationally brokered deal meant to end 13 months of violence.
The unanimous Security Council resolution also called on both sides to immediately "cease all armed violence in all its forms" and asked Syria to pull troops and heavy weapons from population centers -- a truce provision the regime has so far ignored.
The cease-fire is at the center of a broadly backed peace plan by special envoy Kofi Annan. It is aimed at ending a conflict that has killed over 9,000 people and launching talks on the country's political future.
The deployment of observers is seen as crucial for making a truce stick. Annan's spokesman Ahmad Fawzi has said a small advance team is on standby to fly to Syria once the Security Council has approved the mission, to be followed by a larger contingent later on.
The Syrian regime and opposition fighters have traded allegations of scattered violations since the truce formally took effect Thursday. However, Saturday's reports of the use of heavier weapons suggested the cease-fire was coming under increasing jeopardy.
The heaviest fighting Saturday was reported in the central city of Homs, one of the cities hit hardest by the regime crackdown on mass protests that erupted in March 2011 and sought President Bashar Assad's ouster.
Activists said regime forces shelled rebel-held neighborhoods of Homs, killing at least three civilians. The state-run Syrian news agency SANA said rebel fighters fired rocket-propelled grenades at an area of regime loyalists, killing one man.
Sporadic shelling by regime forces in Homs began late Friday and continued Saturday, said the Britain-based Syrian Observatory for Human Rights, an activist group.
"I can see black smoke billowing from a building that was hit in Jouret el-Shayah," local activist Tarek Badrakhan, based in the neighborhood of Khaldiyeh, told The Associated Press via Skype. Badrakhan said the body of the man remained in the street for several hours, with people unable to approach it due to the shelling and sniper fire.
A video posted online by an activist said to be taken in Homs showed shells landing in a heavily damaged street. The Observatory said regime forces also fired mortar shells at neighborhoods in Homs throughout the day.
The Syrian news agency, meanwhile, said rebel fighters fired rocket-propelled grenades at the Homs neighborhood of Zahra, a stronghold of regime supporters. The agency said rebels fired two grenades, waited for people to gather and then fired a third, killing one person and wounding 12.
The regime restricts access of foreign observers, including journalists, making it difficult to verify reports of violence independently.
In the northern city of Aleppo, Syria's largest, four people were killed when security forces opened fire on a funeral procession, the Observatory said.
Also, troops conducted a wave of arrests in the Damascus suburb of Dumair, opening fire on a car that then exploded, killing one man and wounding two others, the Observatory said.
In the southern province of Daraa, rebel gunmen ambushed a car carrying soldiers, killing two, the group reported.
In other attacks blamed on rebels, SANA said gunmen kidnapped army Col. Mohammed Eid Saturday in a suburb of the central city of Hama while on his way to work.
It also reported that gunmen stormed the house of local politician Mohammed Ismail al-Ahmad in the northern town of Tin, shot and wounded him, then took him to an unknown location, SANA said. The agency said Ahmad had been planning to run for parliament.
Activists have reported a total of 19 people killed by regime forces since Thursday, while five people were killed in apparent rebel attacks. Those numbers are still much smaller than the norm before the truce.
Bassem Mroue can be reached on twitter at http://twitter.com/bmroue
Associated Press writer Edith M. Lederer at the United Nations contributed reporting.