BEIRUT, Lebanon — Scattered clashes and reports of a deadly bombing near a Damascus playground marred the first day of a four-day cease-fire in the Syria conflict on Friday, but in most parts of the country the level of violence appeared to subside because of the truce, called in deference to the most important Muslim holiday of the year.

With the threat of violence diminished, protesters emerged in the streets of cities and towns across the country. Syrian state television showed President Bashar al-Assad making a rare public appearance, attending the morning prayers for the start of the holiday, Id al-Adha, or the Feast of Sacrifice, in a central Damascus mosque. There was no sound, but Mr. Assad was seen to be chatting amicably with other worshipers.