Moscow (AFP) - Russia on Tuesday said Syrian regime forces were fully respecting a ceasefire but that rebel fighters had violated it 23 times.
Moscow is one of the main backers of Syrian leader Bashar al-Assad and has been flying a bombing campaign in support of his forces for the past year.
"Syrian government troops have completely stopped firing, with the exception of areas where Islamic State and Jabhat Al-Nusra fighters are active," senior Russian military officer Viktor Poznikhir said in a televised briefing.
"Unfortunately the same cannot be said for armed units of the moderate opposition controlled by the US. After the start of the cessation of hostilities by this morning 23 instances of firing on residential areas and government positions were registered."
The ceasefire agreement for Syria, hammered out between Moscow and Washington, came into force Monday evening and if it holds, could lead to the two sides coordinating strikes against jihadist targets.
In televised briefings from various locations around war-torn Syria, Russian military observers said that rebel violations had taken place in the provinces around Aleppo, Latakia, Damascus, Hama, Idlib and Daraa.
A Russian military officer said that "new violations" had also occurred around the ravaged city of Aleppo during the day.
As the televised briefing cut to a military monitor by the key Castello Road into Aleppo -- a crucial supply route for humanitarian aid which has been under Syria regime control -- gunfire broke out and the Russian officer dived for cover.
There was no way of independently verifying where the firing was coming from.
The truce deal is meant to see both government forces and rebels pull back from the key route to allow aid to enter rebel-held areas of Aleppo.
The Russian military said that the Syrian army had informed them they would be ready to hand over control of a checkpoint on the road to the Syrian Red Crescent at 1900 local time (1600 GMT), with some 20 members of a pro-government militia "for security".