Guns mostly fell silent in Syria and Russian air raids stopped on Saturday, the first day of a cessation of hostilities that the United Nations has described as the best hope for peace in five years of civil war.
Under the U.S.-Russian accord accepted by President Bashar al-Assad's government and many of his foes, fighting should cease so aid can reach civilians and talks can open to end a war that has killed more than 250,000 people and made 11 million homeless.
Russia, which says it intends to continue strikes against areas held by Islamist fighters that are not covered by the truce, said it would suspend all flights over Syria for the first day to ensure no wrong targets were hit by mistake. The agreement is the first of its kind to be attempted in four years and, if it holds, would be the most successful truce of the war so far.