This combination of undated photos show, from left, Abdifatah Yusuf Isse, Salah Osman Ahmed and Omer Abdi Mohamed, three of the four ethnic Somalians sentenced Tuesday for aiding the al Qaeda-linked rebel group al-Shabab.
MINNEAPOLIS -- A federal judge sentenced four men to prison on Tuesday for helping recruit young men in Minnesota to travel to Somalia and fight for the militant group al-Shabab.
Investigators believe about 20 young, ethnic Somali men left Minnesota from 2007 to 2009 to go to Somalia to fight for al-Shabab, which the United States has designated a terrorist organization.
Three men who cooperated with investigators were each sentenced to three years and a fourth man was sentenced to 12 years in prison.
"These defendants, by providing material support to a designated terrorist organization, broke both the law and the hearts of family members across the Twin Cities," U.S. Attorney B. Todd Jones said in a statement.
Eighteen men were charged after a four-year investigation. Eight were convicted and the rest are thought to be fugitives or to have been killed in Somalia while fighting for al-Shabab.
On Tuesday, Omer Abdi Mohamed, 28, was sentenced to 12 years in prison after pleading guilty in July 2011 to one count of conspiring to provide material support to co-conspirators who intended to murder, kidnap, or maim Ethiopian and Somali government troops.
Mohamed, of Minneapolis, admitted that he helped recruits get plane tickets and helped to raise money for them to travel to Somalia to fight with al-Shabab in 2007.
Three men who cooperated with investigators were each sentenced to three years in prison by Chief Judge Michael Davis in Minneapolis federal court. Abdifatah Yusuf Isse, Salah Osman Ahmed, and Ahmed Hussein Mahamud had each pleaded guilty to one count of providing material support to al-Shabab.
Isse, 29, and Ahmed, 30, both of Minneapolis, admitted traveling to Somalia in December 2007, where they both stayed at al-Shabab safe-houses or training camps. They left Somalia together in the spring of 2008.
Mahamud, 28, a Westerville, Ohio, resident who had lived in a Minneapolis suburb, admitted in February 2012 that he helped provide al-Shabab with money and people from 2008 through February 2011.
Isse, Ahmed, and Mahamud testified at the trial of another man, Mahamud Said Omar, who was sentenced on Monday to 20 years in prison for his 2009 conviction on five counts for providing money and aiding the travel of men to Somalia for al-Shabab.
Omar, a Somali citizen who lived legally in the United States, was accused of aiding al-Shabab from September 2007 through August 2009. He was accused of providing hundreds of dollars to al-Shabab for assault rifles and of helping six men travel from Minnesota to Somalia in the fall of 2008.
Also on Monday, Davis sentenced Minneapolis resident Kamal Said Hassan, 28, to 10 years in prison. He admitted going to Somalia, where he trained at an al-Shabab camp and participated in an attack on Ethiopian soldiers, prosecutors said.
Hassan pleaded guilty to two counts of aiding al-Shabab and one of lying to investigators.
The earliest of the travelers left the United States in October and December 2007, followed by more in 2008 and 2009. Two of the travelers, Shirwa Ahmed and Farah Mohamed Beledi are believed to have blown themselves up in attacks in Somalia.