Nashville, Tenn. - A federal judge has delayed the start of a trial for more than a dozen people accused in a sex trafficking ring run by Somali gangs that reached from Minnesota to Tennessee.

Opening arguments were scheduled to start Monday, but over the weekend the U.S. attorney's office released to defense attorneys hundreds of pages of investigator notes and hours of telephone recordings of one of the juvenile female victims.

The indictment said three gangs called the Somali Outlaws, the Somali Mafia and the Lady Outlaws were forcing teenage girls into prostitution and operated in St. Paul, Minn.; Minneapolis; Columbus, Ohio; and Nashville.

The indictment accuses the gangs of finding and recruiting young girls, some also Somali, for the purpose of prostitution in exchange for money and drugs between 2000 and 2010.

Most of the defendants are from the Somali refugee populations in Minnesota and Tennessee.

U.S. District Judge William J. Haynes pushed the start of the trial back one week to give the defense attorneys time to review the additional evidence. Assistant U.S. Attorney Van Vincent told the court that the late release of the documents was not intentional.

Four juvenile female victims are listed in court documents. Out of the total of 30 that were indicted, 15 were originally scheduled to go to trial on charges of sexual trafficking of children by force, fraud or coercion and conspiracy to commit sexual trafficking of children.

The government dismissed some counts against one of the defendants during a hearing Monday, so 14 defendants are scheduled to go to trial next week.

One female juvenile victims, identified in court records as Jane Doe No. 2, is expected to testify when trial resumes. A jury of 19 people has been selected to hear the case.