A U.S.-born Islamist militant on Washington's most wanted list was killed in a gunbattle in Somalia on Thursday, witnesses said, after he fell out with the al Shabaab rebel group's top commander.

Residents in al Baate village in southern Somalia said Alabama-born Omar Hammami, commonly known as Abu Mansoor al-Amriki or "the American", and a British national known as Usama al-Britani were shot dead in a dawn raid on their hideout.

Hammami's killing exposed the rifts in al Shabaab's top ranks as the group affiliated to al Qaeda grapples with an African Union-led military offensive that has captured key cities from the militants, depriving them of revenues.

"This morning al-Amriki and his comrades were attacked by well armed fighters," said village resident Hussein Nur. "After a brief fight al-Amriki and his two colleagues were killed. Several of their guards escaped."

A shopkeeper from the rebel-controlled village heard al Shabaab fighters confirm the deaths and said the militants had closed off the area where Hammami was gunned down.

There was no immediate proof of Hammami's death from al Shabaab.

Hammami's father, Shafik Hammami of Daphne, Alabama, told Reuters he learned of his son's death when he woke up to read the news online. Speaking softly, he said his love for his son was unconditional and hoped he was still alive.

"I read on the Web that the FBI has not confirmed it yet, so I am hoping and praying it is not true," Shafik Hammami said, adding he has not seen or talked to his son since Omar left for Somalia in 2006.
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A FBI handout image of US Islamic extremist Omar H …
A FBI handout image of US Islamic extremist Omar Hammami. Alabama-born Hamami was killed in a shooto …

CONSOLIDATING POWER

Hammami, 29, was among senior-ranking commanders who viewed al Shabaab leader Ahmed Godane as veering from the group's goal of imposing their strict interpretation of Islamic sharia law over the country. Hammami and others were sidelined or killed.

In June, al Shabaab's firebrand spiritual leader Sheikh Hassan Dahir Aweys, also caught up in the rift, fled.

"Godane has consolidated power by removing rivals from the group, including ideological and religious leaders," said Emma Gordon, east Africa analyst at IHS Country Risk, adding it made a more cohesive group capable of launching fresh attacks.

Hammami, who was on Washington's Most Wanted Terrorist list, swiftly gained influence among rebel foreign jihadists fighting to topple a government seen as a Western puppet.

In a growing campaign to challenge al Shabaab, more than 150 clerics signed a government-supported fatwa, or Islamic ruling, against the group on Wednesday, saying its ideology was a threat to Islam.

The government has tried to undermine ideological support for the militants, who formed an alliance with al Qaeda in 2012.

Somalia's embattled central administration is struggling to restore law and order across the country as it emerges from two decades of civil conflict.

A bomb in the port city of Kismayu on Thursday wounded the newly recognized leader of the southern Juba region. Western security sources said the blast had targeted his convoy as it drove through the city.

(Additional reporting by Richard Lough in Nairobi; and Kaija Wilkinson in Mobile, Alabama; Writing by Richard Lough; Editing by Edmund Blair and Paul Taylor)