DUBAI: The Yemen-based branch of al Qaeda has offered a bounty for anyone who kills the US ambassador to Yemen or an American soldier in the impoverished Arab state, a group that monitors websites said.

Al Qaeda in the Arabian Peninsula (AQAP) said it was offering three kilograms of gold for the killing of the US ambassador in Sanaa, Gerald Feierstein, and the US-based SITE Intelligence Group said, citing an audio released by militants.

AQAP will also pay 5 million rials ($23,350) to whoever kills any American soldier in Yemen, it said.

The offer, valid for six months, was made “to encourage our nation, and to expand the circle of the jihad (holy war) by the masses,” SITE said, citing the audio.

AQAP, mostly militants from Yemen and Saudi Arabia, is regarded by the United States as the most dangerous branch of the network founded by Osama bin Laden.

A US ally, Yemen is struggling against challenges on many fronts since mass protests forced veteran leader Ali Abdullah Saleh to step down in February after decades in power.

President Abd-Rabbu Mansour Hadi's government is trying to re-establish order and unify the army.

Washington, which has pursued a campaign of assassination by drone and missile against suspected al Qaeda members, backed a military offensive in May to recapture areas of Abyan province.

But militants have struck back with a series of bombings and killings.