Syria mediator Lakhdar Brahimi, the U.N.-Arab League envoy, has not charted a way forward or said how he would bridge the deep divide between Assad and his opponents. The Syrian president won't resign, and the opposition says it won't negotiate a transition deal until he does.
Brahimi's plan marks the first attempt by the international community in six months to scale back the violence that has displaced hundreds of thousands of people and devastated entire neighborhoods. A more comprehensive U.N. cease-fire plan in April quickly collapsed.
Brahimi did not set clear terms for the truce, perhaps to reduce the possibility of failure. He only said it should be in effect during the four-day holiday, but made no arrangements for monitoring compliance.
A few hours after the truce took effect, a car bomb in a residential area of Damascus, near a housing complex for police, killed 10 people and wounded more than 30, Syrian state media said.
Another rigged car went off near an army checkpoint in the southern city of Deraa, killing three soldiers, said the Britain-based Syrian Observatory for Human Rights, which compiles reports from a network of activists.
Still, there appeared to be a drop in fighting and casualties Friday.
In recent weeks, the daily death toll usually topped 150. From dawn to dusk Friday, 62 people were killed, including 24 regime soldiers, according to the Observatory.
Khaled al-Shami, an activist in Damascus, said he expected the lull to end quickly. "The regime cannot afford to give a truce a chance," he said. "The leadership worries it will breathe new life into the revolution, and they will not let that happen."
However, rebel commanders have also dismissed the truce as irrelevant, while a radical Islamic group fighting on the rebel side, Jabhat al-Nusra, has rejected the cease-fire outright.
Gunmen from the group also took part in fighting Friday near a military camp close to a key supply road to Aleppo, Syria's largest city. In Aleppo, where rebels and regime forces are locked in a stalemate, fighting raged near the military airport, killing at least four people.
Elsewhere, at least 22 people were killed by regime shelling and sniper fire in the Damascus suburbs of Harasta and Douma, and in the northern Idlib province, the Observatory said.