A drone strike killed four suspected Al-Qaeda fighters in central Yemen on Monday, a local official said.

The United States is the only force known to operate armed drones over Yemen.

"A car carrying four fighters was hit as it drove on a mountain road" in Bayda province, the official said. "All of them were killed."

"The fighters were from Al-Qaeda," he said.

Washington considers the Yemen-based Al-Qaeda in the Arabian Peninsula to be the radical group's most dangerous branch.

AQAP has flourished in the chaos of the country's civil war, which pits the Saudi-backed government of President Abedrabbo Mansour Hadi against the Huthi Shiite rebels.

A long-running drone war against AQAP has intensified since US President Donald Trump took office in January.

An air raid he ordered that month killed a US Navy SEAL and several Yemeni civilians in Bayda.

US strikes in Yemen have typically targeted suspected Al-Qaeda fighters, but last month the United States said it had killed dozens of fighters from its jihadist rival, the Islamic State group, at training camps in Bayda.

More than 8,600 people have been killed since a Saudi-led coalition joined the Yemen war on Hadi's side in 2015.