RIVERSIDE, Calif. (AP) – A judge has refused to jail two Marines but found them in contempt of court for refusing to testify against a former squad leader accused of killing unarmed detainees in Iraq.

U.S. District Judge Stephen Larson rejected a plea Friday by a prosecutor to jail Sgt. Ryan Weemer and Sgt. Jermaine Nelson. Instead, he ordered them to return to court in 30 days to begin proceedings on the contempt charges.

Weemer and Nelson were previously given immunity by Larson to testify in the case charging Luis Nazario Jr. with shooting and killing unarmed detainees in November 2004 in Fallujah.

The two were told their testimony would not be used against them in their own military cases involving detainee deaths. They declined to accept immunity because their attorneys do not believe their testimony would be withheld from their upcoming courts martial.