For several months the FBI has been investigating at least 20 Somali-American men from the Minneapolis area and elsewhere in the United States who traveled to war-torn Somalia to join an Al Qaeda-linked terrorist group known as al-Shabaab, which has been warring with the moderate Somali government since 2006. At a Senate hearing on the issue last month, one top-ranking official said it's 'clear' the Internet played a role in radizalizing and recruiting the young men.

VIDEO: Click here to watch Catherine Herridge's report.

The 30-minute video posted this week is a highly polished production, featuring anti-American hip-hop and sporadic images of Usama bin Laden. In much of the video, a man dubbed 'The American' purportedly leads a group of al-Shabaab militants in an ambush of Ethiopian forces, which oppose an Islamic state and have backed the new Somali government.

'The only reason we are staying here, away from our families, away from the cities, away from candy bars [and] all these other things is because we are waiting to meet with the enemy,' he tells them in the video, first provided to FOX News by the Washington-based Middle East Media Research Institute (MEMRI). 'They're supposed to be coming anytime. We're going to set up the ambush, and by the will of [God] we're going to kill all of them.

MEMRI identified 'The American' as Abu Mansur al-Amriki, and a law enforcement official said he is originally from the United States, but has been in Somalia 'for some time.' The official said al-Amriki is in his late 20s or early 30s. The official wouldn't offer any other identifying features, including whether he had converted to Islam.

MEMRI described the video as a 'clear appeal to foreign youth, especially in English-speaking countries, to join the jihad in Somalia.'

In the video, 'The American' praises a man killed in the fight, saying, 'We want to inform his family that he was one of the best brothers here. ... We need more like him, so if you can encourage more of your children and more of your neighbors, anyone around, to send people like him to this jihad it would be a great asset for us.'

Another man, with an accent and a wrap covering his face, says at the end of the video, 'We're calling all the brothers overseas, all the Shabaab, wherever they are, to come and live the life of a [fighter], and they will ... love it.'

The FBI investigation into how young American men were recruited to join al-Shabaab in Somalia is active in Columbus, Ohio; Cincinnati, Ohio; Boston; Seattle; and San Diego, according to testimony from counterterrorism officials and others at the Senate hearing last month.

But reports from around the world suggest young Muslims from other Western countries, namely Canada, Australia and England, are also being recruited to join the fight in Somalia.

U.S. officials declined to comment specifically on whether officials from those countries have been working with the FBI.

But at a State Department briefing today, State Department spokesman Robert Wood said, 'Somalia would be one of those areas that we're concerned about with regard to Al Qaeda recruitment. This requires broad cooperation, the United States with other countries — not only in the Horn of Africa but outside of that region — to try to do what we can to prevent Al Qaeda from being successful in recruiting young people to their cause.'

Click here to read previous reports:

• Grand Jury Convenes in FBI Terror Case Against Somali-Americans
• Source: Missing Somali-American Spotted at Minneapolis Shopping Mall
• Source: 'Several' Missing Somali-Americans Back in U.S. After Overseas Terror Mission
• Missing Somali-American Men Found...On Facebook
• Alleged Al Qaeda Sleeper Agent Ali al-Marri Won't Be Released on Bond