Yahya Arhab / EPA, file

The Yemen branch of al-Qaida has put out a bounty on U.S. Ambassador Gerald Feierstein, shown earlier this month at a military conference in Sanaa.

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

Al-Qaida in the Arabian Peninsula (AQAP) said it was offering 3 kilograms (more than 105 ounces) of gold for the killing of Ambassador Gerald Feierstein, the U.S. ambassador based in Sanaa, the U.S.-based SITE Intelligence Group said, citing an audio released by militants.

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

Citing the audio, SITE said the offer was put out as being valid for six months and was made "to encourage our Muslim Ummah (nation), and to expand the circle of the jihad (holy war) by the masses."

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AQAP, made up mostly of 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.

In September, AQAP urged Muslims to step up protests and kill U.S. diplomats in Muslim countries over a film denigrating the Prophet Mohammad, which it said was another chapter in the "crusader wars" against Islam.

The film provoked an outcry among Muslims, who deem any depiction of the Prophet as blasphemous and triggered violent attacks on embassies in countries in Asia and the Middle East.

Four U.S. officials, including the ambassador to Libya, were killed in the aftermath. The Pentagon said it had sent a platoon of Marines to Yemen after demonstrators stormed the U.S. Embassy in Sanaa.

A U.S. 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.

Key al-Qaida figure killed

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-Qaida 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.

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