Al-Shabaab, an Al-Qaeda-linked terrorist group that controls much of Somalia, has released a new audio tape from a 25-year old American convert to Islam who joined their ranks, accompanied with a photo of the individual, FoxNews.com reports.

The convert, Omar Hammimi, who is now called Abu Mansour al-Amriki, is described in the article as "one of the most outspoken voices of terrorist propaganda."

Hammimi first appeared on the Arab TV station, Al-Jazeera in October 2007, but disguised his face. He first showed his face in a terrorist propaganda tape released in April, which praised Osama Bin Laden and featured hip-hop music.

His decision to go to Somalia to fight alongside terrorists has surprised his former friends and colleagues. They point to his reaction following the attacks of September 11, 2001.

"Everyone was really shocked. Even now it's difficult to believe a Muslim could have done this," the school newspaper, The Vanguard, quoted him as saying when he attended the University of South Alabama, where he was the president of the Muslim Students Association.

This is a sharp contrast to al-Amriki's rhetoric today.

"Despite the fact that you [President Obama] have been humbled by the Mujahideen and forced to at least pretend to extend your hand in peace to the Muslims, we cannot and shall not extend our hands. Rather, we shall extend to you our swords until you leave our lands," he is quoted by  The Vanguard as saying in a videotape over the summer. The Middle East Media Research Institute was the first to provide a translation of the tape.