By Paul Cruickshank
American Omar Hammami, who built a following in militant circles in the West for his idiosyncratic jihadist rap videos and had a U.S. bounty on his head, was among two notable jihadists reportedly killed in Somalia on Thursday.
Sources said Hammami and Briton Osama al-Britani were apparently ambushed west of Mogadishu by members of al Qaeda affiliate Al-Shabaab.
A message posted on the al-Jihad al-Alami forum said they were killed "by an unjust raid by the Emir of the Shabaab al-Mujahideen Movement and his followers in Islamic Bay and Bakool province after clashes that lasted for several hours while they defended themselves," according to a translation by the SITE intelligence group.
Hammami, a former Al-Shabaab fighter and prolific English-language propagandist for the group with a $5 million American bounty on his head, went into hiding after falling out with the group last year.
Hammami – who also goes by the name Abu Mansour al Amriki – has been falsely reported killed in the past and CNN cannot independently confirm his death.
However John Berger, an American terrorism expert who has closely tracked Hammami and has recently communicated with him extensively online, believes that the latest reports are credible.
"I'm pretty sure it's true. I saw it from sources close to Hammami and also from the Shabaab side, which hasn't happened before," Berger told CNN.
The United States was working to confirm the report.
"We have seen reports that Omar Al-Hammami, also known as "Al-Amriki," was killed in Somalia, and we are working to verify the reports," a State Department official said.
Hammami released a bizarre internet video in March 2012 claiming the group was trying to assassinate him due to what he explained were "some differences that occurred between us regarding matters of the sharia and matters of strategy."
One of his grievances appears to have been that he was passed over for promotion.
Hammami's father is Syrian-born and his mother an American. He grew up in Daphne, Alabama, a suburb of Mobile.
After his family moved to Egypt in 2006, Hammami left with a friend to join Al-Shabaab and quickly climbed the ranks as more foreign fighters converged on Somalia, especially young Somali-Americans. Subsequently he was indicted in federal court in the United States on terrorism charges.
Following the release of his video, he railed against several high ranking figures in Al Shabaab, including its leader Moktar Abu Zubayr, on his Twitter account, in a self-published autobiography he released online, and in a series of online exchanges with Berger.
He alleged that Al Shabaab leaders lived extravagant lifestyles from taxes imposed on Somalis, treated foreign fighters poorly, and lacked ambition to fight Jihad globally.
He even accused Zubayr of having engineered the shooting of Fazul Mohammed, al Qaeda's leading operative in east Africa, by directing him to a Somali government checkpoint in Mogadishu where he was killed in June 2011.
These accusations became a growing irritant to Al Shabaab.
In January Hammami tweeted the group had issued an ultimatum that he surrender or be killed. In April, he posted a picture of himself with what he claimed was a gunshot wound in his neck from an attempted assassination attempt.
By then, he had aligned himself with Sheikh Hassan Dahir Aweys, a powerful member of Al Shabaab's old guard and former head of the Islamic Courts Union, a militia which briefly took over much of Somalia in 2006.
In June, Aweys surrendered to Somali authorities after reportedly defecting from the group after losing out in a power struggle with the younger and more harline Zubayr.
Al Shabab has increasingly turned its guns inward since it was pushed out of Mogadishu and the lucrative port city of Kismayo after an offensive by Kenyan and Somali government troops.
One of the sources of internal disagreement was Zubayr's decision to formally merge Al Shabaab with al Qaeda in February 2012 which caused discomfort to some powerful figures in Al Shabaab, including Aweis. Rivalry between different clans also increased tensions within the group.
Despite losing ground, Al Shabaab has remained a threat inside Somalia.
Last week, it claimed responsibility for bombing a restaurant in Mogadishu popular with westerners killing more than a dozen people.
Several Americans are still believed to belong to the group. These include Jehad Serwan Mostafa, who also has a $5 million U.S. price tag on his head and who sources tell CNN has risen to a leadership position in the group.
Hammami gave an interview last week to Voice of America's Somali service in which he renewed his attack on Zubayr. It may have been the final straw for Al Shabaab's commander.
Hammami not only claimed Zubayr was trying to have him killed but depicted him as an oppressor of Muslims.
Hammami said in the interview that he was hiding in a forested area after Al Shabaab fighters arrested both of his wives and killed a person who had arranged a safe house for them.
"I'm openly not from Shabaab, I'm openly not from al-Qaeda, but I'm definitely a terrorist," he said, adding he would only come back to the United States "in a body bag."