Seven suspected al-Qaeda militants were killed in an apparent U.S. drone strike on the Yemeni port city of Mukalla which the militants overran earlier this month, a local official said Wednesday. The overnight strike hit a vehicle parked near the presidential palace in Mukalla, capital of Hadramawt province, witnesses said. The United States, whose intelligence agencies consider the Yemen-based al-Qaeda in the Arabian Peninsula (AQAP) to be the most dangerous branch of the militants network, is the only country that operates drones over the war-torn country. On April 14, AQAP announced the death of one of its ideological leaders, Ibrahim al-Rubaish, in a similar drone strike in Hadramawt. Al-Qaeda has exploited fighting between rebels and beleaguered government forces backed by a Saudi-led coalition to consolidate its grip on the southeastern province. U.S. Defense Secretary Ashton Carter has acknowledged that al-Qaeda is gaining ground but has vowed that Washington will keep up its battle against the group.