A partial truce known as a “regime of calm” has come into effect in most parts of Syria apart from the divided second city of Aleppo.
The truce announced by the Syrian Army became operational in two areas an hour after midnight local time on Friday.
A statement said it would last for 24 hours in Damascus and the Eastern Ghouta region outside the capital. The truce is also due to last for 72 hours in the northern countryside of Latakia province, BBC reported.
There has been no explanation as to why the halt in fighting is only temporary.
More than 230 people are estimated to have been killed in the past eight days of deepening violence there.
During the day, rocket barrages fired by militants were reported to have killed 15 worshippers after Friday prayers in a government-held part of Aleppo.
The Malla Khan Mosque in Bab al-Faraj was hit, government officials said, causing heavy casualties. Some of the injured were in a serious condition and were likely to die, state television said.
In the militant-held east, government airstrikes reportedly left at least 11 dead.
The BBC’s Jim Muir said the partial truce is the result of high-level contacts between the Americans and Russians who are being urged by the UN and others to pull out all the stops to shore up the collapsing cessation of hostilities that came into effect two months ago.
Under the new arrangement, the Syrian Army says the objective of the “regime of calm” is to deprive the militants, or terrorists, of a pretext for hitting civilian targets and to bolster the existing ceasefire.
The Americans are hoping that it will calm hostilities in those areas, and that the process can be extended to the biggest current trouble spot, Aleppo, which the Russians are reported to have refused to include in the latest truce.
Large parts of the city have been destroyed and its infrastructure has been severely damaged, leaving civilians without water and electricity for months.
The UN High Commissioner for Human Rights, Zeid Raad Al Hussein, said the failure of the Security Council to refer the situation in Syria to the International Criminal Court was “an example of the most shameful form of realpolitik”.
Russia and the US are backing opposing sides in the conflict.
