DAMASCUS, Syria — Syrian troops advanced in a strategic suburb of Damascus and bombarded other areas around the capital Saturday in a push to secure President Bashar Assad’s seat of power as rebels make gains in the north.

A government official said regime forces had taken much of Daraya, an area on the edge of a major military air base just south of the capital, after nearly two months of heavy fighting that anti-regime activists say has killed dozens of people and uprooted tens of thousands more from their homes.

The announcement came a day after rebels and Islamic militants seeking to topple Assad took full control of the northwestern Taftanaz air base in a significant blow to the military.

In other violence, athletic champion Hisham Raqsha was shot to death in Damascus while on his way back home, according to the Observatory and state-run news agency SANA.

SANA said Raqsha was the coach of Syria’s walking team.