A man who blew himself up in an attack in the Somali capital on Saturday reportedly grew up in Minneapolis and was known by the FBI as one of 20 Somali Americans to have joined an al-Qaida-linked militant group.
Abdisalan Hussein Ali, 22, was suspected of being a member of al-Shabab, the FBI told msnbc.com.
Kyle Loven, the FBI's chief division counsel for Minneapolis, said Ali was a subject of "Operation Rhino," an ongoing investigation into Somali youth traveling from the U.S. to Somalia to fight for al-Shabab.
Loven could not confirm whether Ali was indeed the bomber but told msnbc.com that the FBI was "awaiting results from DNA checks at this point."
Al-Shabab posted an audiotape that they said was made by Ali before he blew himself up during an attack Saturday on an African Union base in Mogadishu that left at least 10 people dead.
The FBI could not confirm whether the audiotape was authentic but was investigating its credibility.
A spokesman for the Somali affairs unit at the U.S. Embassy in Nairobi told msnbc.com that they had seen reports alleging that one of the bombers was an American citizen. "We have not been able to verify those reports," Matt Goshko said.
In the tape, the young man, who would be at least the fourth American to become a suicide bomber in Somalia, urges other young people to not "just chill all day" and instead fight nonbelievers around the world.
The website Somalimemo.net (website not in English), often used by the al-Shabab militia, said the Somali-American bomber had emigrated to the U.S. when he was two years old.
There were conflicting reports of his name, with some sources naming the bomber as Abdisalan Taqabalahullaah and Cabdi Salaam al-Muhajir.
But a Somali diplomat at the United Nations said the youth's friends and family listened to the recording and identified him as Abdisalan Hussein Ali, .
"They all say it is him," Omar Jamal, the diplomat, told The Times.
According to The Minneapolis Star Tribune, he graduated from Edison High School and attended the University of Minnesota, where he was a pre-med student, The Times reported. He disappeared in 2008.
The Star Tribune reported that Ali's nickname was "Bullethead," and that during high school he liked to lift weights and that he sold shoes to help support his family.
The young man in the tape had an American accent and mixed Muslim terminology with American slang as he urged Muslims to carry out attacks against non-Muslims around the world.
"My brothers and sisters, do jihad in America, do jihad in Canada, do jihad in England, anywhere in Europe, in Asia, in Africa, in China, in Australia," the voice on the al-Shabab tape said. "Anywhere you find (unbelievers), fight them and be firm against them.
"Today jihad is what is most important thing for the Muslim ummah," he said, using a word for the Islamic community. "It is not important that you, you know, you you become a doctor or you become, you know, uh, some sort of engineer."
"We have to believe in Allah and die as Muslims ... Brainstorm," the youth said. "Don't, don't just sit around and, you know, be, be be a couch potato and you know, you know, just like, you know, just chill all day, you know. It doesn't, it doesn't, it will not benefit you, it will not benefit yourself, or the Muslims."
Disguised as soldiers
In Saturday's attack in Mogadishu, two suicide bombers blew themselves up near the entrance to the African Union compound and armed attackers then jumped over the base's walls, sparking a two-hour gunfight that left at least 10 people dead, according to security officials.
The AU has not released official casualty figures but al-Shabab said dozens died.
"They were dressed in Somali military uniform and disguised as ordinary soldiers," a Somali soldier, Col. Nor Abdi, said. "Then they tried to enter the base and (AU) soldiers fired at them. Then heavy gunfire started and all of them were killed. I don't know how many they were but they were more than 10 men."
About 9,000 AU peacekeepers supporting Somali government troops have almost pushed al-Shabab from the capital of Mogadishu.
Earlier this month, Kenya opened a second front, sending hundreds of soldiers across the border into southern Somalia.
The insurgency is outgunned by both forces and has been weakened by a famine in its strongholds. But it still maintains the ability to carry off spectacular attacks, like a truck bomb that killed more than 100 people earlier this month, or Saturday's two-hour attack on the AU base.
Somalia has not had a functioning government in more than 20 years.