A senior Al-Qaeda operative in Yemen with a $5 million US bounty on his head was killed Thursday in one of two suspected American drone strikes in the war-torn country.

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

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

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.

The US State Department said Belaidi was a regional AQAP emir, responsible for multiple provinces in Yemen.

It offered a $5-million reward for information on Belaidi over his alleged involvement in plotting bomb attacks on Western diplomatic officials and facilities in the capital Sanaa in 2013.

Born in Abyan, Belaidi 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.

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

The unmanned aircraft targeted an vehicle in Rodhoum area, killing its six passengers, the official said.

The US has kept up strikes on jihadists during months of fighting between pro-government forces and Iran-backed Huthi rebels who control large parts of Yemen, including Sanaa.

Loyalists backed by a Saudi-led coalition have recaptured Aden, Lahj and three other southern provinces from Shiite rebels since July.

- Jihadists gains -

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

Azzan lies on the highway between Shabwa's provincial capital Ataq and the city of Mukalla, the capital of the vast desert Hadramawt province overrun by jihadists in April.

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

The US's long-running drone campaign in Yemen dealt a blow to AQAP in June, when a strike killed the group's leader Nasir al-Wuhayshi. He was replaced by AQAP military commander Qassem al-Rimi.

Islamists have been behind a surge in attacks on security installations and officials in Aden, which has been chosen as a temporary base for the government.

On Wednesday, a suicide bomber attacked the convoy of Lahj police chief Colonel Adel al-Halemi in northeastern Aden. A guard and a 12-year-old boy were killed in the car bomb while Halemi sustained light wounds, security officials said.

More than 5,800 people have been killed since the coalition launched an air and ground war against the rebels in March, according to the United Nations.