DAMASCUS, Syria — Syrian troops have captured most of a strategic Damascus suburb used by rebels as a base to threaten key regime facilities in the capital, a government official said Saturday.

The announcement that regime forces had taken Daraya was made a day after antigovernment activists said rebels and Islamic militants seeking to topple President Bashar Assad took full control of Taftanaz air base in the northwest. That dealt a significant blow to Assad’s military, with helicopters, tanks, and multiple rocket launchers seized.