Al-Shabab's recruitment of Somali youth in America poses a threat to U.S. security, the director of a Minnesota-based organization told Congress on Thursday.

Speaking before a House Foreign Affairs Committee, Mohamed Farah told members that Al Shabab preys on "disenfranchised" Somali youth and that agencies should devote more resources to "eliminate this cancerous ideology."

The federal government must team with local organizations "to deter youth from becoming radicalized," said Farah, executive director of Ka Joog.

The youth group, which means "stay away" in Somali, has battled Al-Shabab's recruiting efforts In Minnesota. Federal law enforcement officials estimate that at least 20 young men have left the state to join Al-Shabab's ranks since 2007. Al-Shabab is Al-Qiada's affiliate in Somalia.

"Why is it that we spend millions of dollars on counterterrorism [efforts] and still American citizens are disappearing and fighting alongside with Al-Shabab?" he asked.

Farah's remarks came amid heightened concerns among U.S. law enforcement and intelligence agencies about the possibility that Al-Shabab may be plotting attacks the United States. Two weeks ago, the group killed dozens of shoppers and injured hundreds during an attack on a shopping on a shopping mall in Nairobi, Kenya.

Through social media sites, Al-Shabab has claimed that Somali-Americans recruited from Minnesota helped carry out the mall attacks. The reports have not been confirmed.

"We must re-examine what we thought we knew about the organization," said U.S. Rep. Eliot Engel of New York, the lead Democrat on the committee.

Analysts testifying at the hearing downplayed the threat of an attack on U.S. soil, saying that Al Shabab is more likely to launch more attacks in Africa.

But the threat of carrying out strikes in the United States remains.

"Al-Shabab has the capability to conduct operations outside Somalia," said Seth Jones, a RAND Corp. security analyst.

"Second, they have an interest in targeting the United States, it embassies and its citizens, with kidnappings as well as killings. Three, they've been recruiting in American cities, including over the internet," Jones said. "You put all those three elements together and yes, there should be concern."

Foreign Affairs Committee Chairman Ed Royce, a California Republican, warned that the U.S. must do more to counter Al-Shabab's recruitment and propaganda efforts.

"Al-Shabab has demonstrated a unique ability to recruit members … in the United States and Europe to travel to Somalia and join their fight," he said. "We need to be on top of this group's … reach into the United States."