The drone "fired four missiles on three Al-Qaeda militants sitting near the port of Mukalla, killing them immediately" yesterday, said the official.
The strike killed a "leading figure" within Al-Qaeda, the official said, without disclosing his name.
Al-Qaeda in the Arabian Peninsula (AQAP) has exploited months of fighting in Yemen between Iran-backed rebels and the beleaguered Saudi-backed government to consolidate its grip on Hadramawt's provincial capital Mukalla -- a city of more than 200,000.
The United States considers AQAP to be the extremist group's deadliest global franchise and regularly targets its militants with armed drone strikes on Yemeni territory.