Man who pleaded guilty testifies at Minnesota terror trial

Supporters and family members of Somali men standing trial rally for a protest in front of the United States Courthouse, Monday, May 9, 2016 in Minneapolis. Six defendants have pleaded guilty to conspiring to provide material support to the Islamic State group. Three defendants have pleaded not guilty. Another man is at large, believed to be in Syria. (Elizabeth Flores/Star Tribune via AP) MANDATORY CREDIT (The Associated Press)

FILE - This undated file photo provided the Sherburne County, Minn., Sheriff's Office shows Abdirahman Yasin Daud, one of several Minnesota men accused of conspiring to travel to Syria to join the Islamic State group. Jury selection in the trial for Daud and two other men began Monday, May 9, 2016, in Minneapolis. (Sherburne County Sheriff's Office via AP, File) (The Associated Press)

FILE - This undated file photo provided by the Hennepin County Sheriff's Office shows Guled Omar, one of several Minnesota men facing trial for allegedly plotting to join the Islamic State group. Jury selection in the trial for Omar and two other men began Monday, May 9, 2016, in Minneapolis. (Hennepin County Sheriff's Office via AP, File) (The Associated Press)

A key prosecution witness has begun testifying in the federal trial of three Minnesota men accused of plotting to travel to Syria to join the Islamic State group.

Twenty-year-old Abdullahi Yusuf took the stand Friday to testify against what he called his three "former friends."

Yusuf is among those who have pleaded guilty. The Star Tribune reports he testified that he intended to leave the U.S. and fight alongside Islamic militants in the Middle East. Yusuf says he chose to cooperate with the government because what he was doing "was not right."

Minnesota Public Radio News reports he admitted Friday that even after he agreed to cooperate with the government, he withheld information.

All three defendants have pleaded not guilty to multiple charges.