"Within last 24 hours, 13 bombardments performed by illegal armed formations have been registered in the provinces of Damascus (6), Aleppo (6) and Hama (1)," the center said in a daily bulletin posted on the Defense Ministry's website.
It added that the Jabhat Fatah al-Sham group shelled a number of neighborhoods in the city of Aleppo.
A nationwide ceasefire between Syrian government troops and several opposition factions came into being at midnight local time on Friday (22:00 GMT on Thursday). Russia and Turkey serve as guarantors of the deal which paves the way for negotiations between the warring parties.
The Jabhat Fatah al-Sham, formerly known as al-Nusra Front, and Daesh terrorist groups, which have been outlawed in Russia, are not part of the ceasefire deal.
