An air strike believed to have been carried out by a US drone in south yemen on Thursday killed a prominent chief of Al-Qaeda's branch in the war-torn country, a family member said.

Jalal Belaidi, alias Abu Hamza, a top commander of Al-Qaeda in the Arabian Peninsula (AQAP), was killed along with two guards in the Maraqesha area of Abyan province, the relative said.

The United States is the only country known to operate armed drones over Yemen, home to AQAP, considered by Washington as the jihadist group's most dangerous affiliate.

A tribal source also confirmed the death of Belaidi following contact with AQAP militants in the area.

Belaidi, who was born in Abyan, served in the past as the leader of Al-Qaeda in Zinjibar, but he is said to have climbed the ranks of the jihadist group to became a top military commander.

The US has kept up strikes on jihadists during months of fighting between pro-government forces and Iran-backed Huthi rebels who control the capital.

Late Wednesday, a drone strike killed six suspected members of AQAP in nearby Shabwa province, a security official said.

Jihadists, including AQAP and the Islamic State group, have gained ground in the south, with AQAP fighters seizing the town of Azzan in Shabwa earlier this week.

Al-Qaeda militants control Abyan's provincial capital Zinjibar and the nearby town of Jaar. They move freely between Hadramawt, Shabwa and Abyan.