The officials say the airstrike took place today night in Mukalla, the capital of Yemen's sprawling eastern Hadramawt province. The explosion was heard in some parts of the city.
Al-Qaeda's Yemen branch, considered to be the most dangerous offshoot of the terror network, has made gains in the province and captured Mukalla earlier this year.
The officials say at least five other militants were wounded in the airstrike. The officials spoke on condition of anonymity because they are not authorized to talk to reporters.
Al-Qaeda has profited from the turmoil that has engulfed Yemen and US drones have continued to target top al-Qaeda leaders there.