Fighting continued in the rebel-held Eastern Ghouta area in Syria during the first daily five-hour "pause" ordered by the government's ally Russia.
Activists said there were government air and artillery strikes, while Russia said rebels shelled a "humanitarian corridor" meant to let civilians leave.
As a result, there were no UN aid deliveries or medical evacuations.
Some 393,000 people are trapped in the enclave near Damascus, which has been besieged by the government since 2013.
Medics say more than 500 people have been killed since the government intensified its bombardment nine days ago in an attempt to retake the enclave.
Meanwhile, France has urged Russia to use its influence over Syrian President Bashar al-Assad to secure a 30-day truce covering the whole country.
The UN Security Council unanimously passed a resolution demanding a nationwide cessation of hostilities on Saturday, but it did not specify a start date.
"Russia is one of the only actors that can get the regime to implement the resolution," French Foreign Minister Jean-Yves Le Drian told his Russian counterpart Sergei Lavrov at a meeting in Moscow.
The Russian defence ministry announced that government forces would "cease strikes on terrorists" from 09:00 until 14:00 local time (07:00-12:00 GMT) daily "with the aim of immediately saving the peaceful population"
One "humanitarian corridor" had been prepared, with help from the Syrian Arab Red Crescent, to allow civilians to leave and the sick and wounded to be evacuated, it said.
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