An al Qaeda leader and four militants were killed in a U.S. drone strike on their vehicle south of Yemen's capital Sanaa late on Wednesday, a government official said.

Washington has stepped up attacks on al Qaeda in the Arabian Peninsula (AQAP) - considered by Western governments to be one of the most dangerous arms of the global militant network.

The group exploited widespread anti-government protests in 2011 to seize swathes of territory in the southern part of Yemen, before being driven back in a U.S.-backed offensive in June last year.

The leader, named as Hamid al-Radmi, died with four of his followers in the town of Wessab in Dhamar province, the official told Reuters on condition of anonymity.

Shoring up stability and security in Yemen is a priority for the United States and its Gulf Arab allies because of the country's location next to the world's top oil exporter, Saudi Arabia, and key shipping lanes.

The United States does not usually comment on strikes by its pilotless aircraft in Yemen. 

The Yemeni government tolerates such strikes but also usually does not comment on the U.S. role in specific incidents.

In January, Yemeni sources said a U.S. drone killed at least six suspected al Qaeda members in a strike on their vehicle in northern Yemen.

Reuters