Syria rebels 'seize Marj al-Sultan base near Damascus'
Syrian rebels say they have captured a military airbase near the capital, Damascus, after a battle in which two helicopters were destroyed.
The area around the base in Eastern Ghouta has been in rebel hands for some months.
Activists also reported that fighters were besieging a military airport in the eastern province of Deir Ezzor.
The UN estimates that at least 20,000 people have died in Syria's uprising.
Activists believe 40,000 people have lost their lives since protests against Bashar al-Assad's rule began in March 2011.
While rebels have made advances in northern and eastern Syria, government forces have fought back whenever they have claimed control of bases near Damascus. The rebels have also been unable to make substantial progress in the capital itself and the second city, Aleppo.
Fifty people were killed in violence on Sunday, according to activist group Local Co-ordination Committees, with most of the victims in Damascus and its suburbs.
Unconfirmed reports said government forces had targeted shelling at several areas close to the capital.
Rebels took control of the Marj al-Sultan base 9 miles (15km) from Damascus on Sunday morning, activists of the UK-based Syrian Observatory for Human Rights said.
Amateur video emerged showing a rebel standing beside a wrecked helicopter while a man speaking on the video said a warplane had been blown up. Other footage purported to show rebels walking around the Marj al-Sultan base.
The Observatory also said fighters were trying to storm the military airport in Deir Ezzor.
The group, whose information cannot be independently verified, is one of the most prominent organisations documenting and reporting incidents in the conflict.