Dozens of young Somali men in the Minneapolis-St. Paul area have disappeared in recent months, causing community members and U.S. intelligence officials to fear that they are joining jihadist groups in Somalia.

Officials are especially concerned that some of the men may be destined to return to the U.S. after they have received terrorist training.

The missing young men have been the focus of some attention since late October, when Shirwa Ahmed, a naturalized U.S. citizen, died in a suicide bombing in northern Somalia. Ahmed was a 1999 graduate of Minneapolis's Roosevelt High School.

• Click here to see photos of the terrorist groups and families of the missing.

The Twin Cities media have reported that a number of other young Somali men — estimates range from six to 40 — have disappeared from the area. Multiple sources within the local Somali community and U.S. government fear that these men may have returned to Somalia to train, or to participate in jihad against the country's secular transitional federal government (TFG).

The TFG has lost ground to Islamist insurgents since early 2007; its primary protection comes from Ethiopian forces that intervened in Somalia in late 2006.

"I've come across 10 to 15 mothers crying because their sons are missing," said Omar Jamal, executive director of the Minneapolis-based Somali Justice Advocacy Center.

A senior U.S. military intelligence analyst said the number may be even higher, since not all of the families whose sons have gone abroad will report it.

Jamal said the Somali community has seen young men disappear in a number of countries across the world, including Canada, the Netherlands and Australia. Multiple sources within the Somali community have corroborated this account.

Dahir Jibreel, who previously served as the TFG's permanent secretary in charge of international cooperation, said, "Other young Somalis went missing in Europe, Saudi Arabia and elsewhere." Jibreel said many of the disappearances occurred simultaneously.

The Somali men who have vanished in Minneapolis are diverse in their education level and job prospects. Some were reportedly linked to Somali gangs, while others have been described as intelligent and studious. Some attended college and appeared to have good job prospects.

There is little evidence that these men were radicalized when they entered the U.S.

Abdiweli Ali, an associate professor of economics at Niagara University and a former adviser to the TFG, said young Somalis are being targeted for indoctrination.

"There's a huge underclass," he said, "and the kids get involved in gangs and drugs. So every time a kid goes to hang out in the mosque, the parents see that as good. They encourage their kids to go to after-school programs with religion, to youth groups at the mosque."

The youths are susceptible to "brainwashing," Ali said. "They are very young, susceptible to any kind of indoctrination. All you need is one rogue imam who tells them the wrong things, and they are susceptible to that."

A senior American intelligence source confirms that Somalis have vanished in the U.S., Canada, Europe, and Australia, adding that some people from the Caribbean also appear to have left for Somalia. And not all of the people bound for training or jihad in Somalia have a Somali background, the source said.

A man who appears to be Caucasian and is aligned with the Somalia-based terrorist group Shabaab can be seen in a recent jihadist video, and another gave an interview with al-Jazeera (though he wore a facemask when doing so). The source said that at least three African-Americans from the Minneapolis area also are suspected of traveling to Somalia to join jihadist groups.

While Somalis in the Minneapolis-St. Paul area have been puzzled by the simultaneous disappearances in multiple countries, the intelligence source says it can be explained by the reopening of certain training facilities in Somalia, such as those in Ras Kamboni. "School is open for business, so the demand has gone up," he said.

The intelligence source said there is a transportation network in place to move fighters to Somalia, including Ruben Luis Shumpert (a Seattle-area barber who was killed this year while fighting for the Shabaab) and Daniel Joseph Maldonado (a U.S. citizen who was arrested in 2007 for undergoing terrorist training). The network apparently has provided forged passports on some occasions, he said.

It is not clear is who is funding the expensive cost of traveling to Somalia. Virtually all of the Somalis who have disappeared in Minneapolis are from impoverished backgrounds.

The size of the recruiting network in the U.S. isn't known, and estimates vary widely. But a major concern is what will happen when these young men return to the U.S. after having undergone terrorist training or participated in combat.

"Ethiopia has announced that they are planning to withdraw from Somalia," said the intelligence source. "So this problem is just going to get worse."

Click here for a FOXNews.com profile of terrorist group Shabaab al Mujahideen.

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