SANA, Yemen — A drone aircraft fired into a group of people preparing to attack Yemeni troops Thursday, killing a man identified as a leader of the local branch of Al Qaeda and at least eight other potential attackers, according to Yemeni and security officials, who said the drone was US-operated.

The strike was in an area less than a mile from a Yemeni brigade position in the southern province of Abyan, the officials said. One of the dead was identified as Nader Al Shaddadi, one of the top leaders of Al Qaeda in the region. An explosive belt wrapped around his waist was defused by members of the brigade.