A German court says a group of Islamic extremists who patrolled the streets of the city of Wuppertal in orange vests with the words "Sharia police" can be tried for violating laws against wearing uniforms with political messages.

The Duesseldorf state court on Tuesday reversed a lower court's dismissal of the case after prosecutors appealed.

The group of nine men made headlines in 2014 when they attempted to establish "Sharia police" in Wuppertal to enforce a strict interpretation of Islam. They patrolled some parts of the city repeatedly asking people to stop drinking alcohol or visiting nightclubs.

One, Sven Lau, was also indicted by federal prosecutors last month on suspicion of supporting a foreign terror group.