Thirty people, 18 of them Islamist fighters, were killed in clashes Wednesday in the districts of eastern and western Ghouta, Dukhania and al Khalamun.
Besides, eight civilians, including three children and a woman, died in air raids launched by the Syrian army on the village of Duma.
Fighting has intensified during the past week in Duma and other areas surrounding the Syrian capital.
Syrian government forces have stepped up their raids on Duma, a rebel stronghold on the outskirts of Damascus, from where the insurgents fire mortar shells into neighbourhoods of the capital.
The number of documented and verified deaths in the Syrian armed conflict between March 2011 and April 2014 is 191,369, including 9,000 children, according to the UN.