Citing a possible terror threat, German police have temporarily pulled the plug on the Rock am Ring festival at the famous Nürburgring race track in western Germany, according to dw.com. Visitors were told to clear the festival grounds.

Authorities suspended the crowded event on its opening night on Friday. The move was based on “concrete leads, which do not allow us to eliminate a possible terror threat,” the police said.

“We are currently conducting a very intense investigation,” authorities added.

The three-day festival was expected to welcome up to 90,000 visitors with German hard rock giants Rammstein set to play on the opening night.

The organizers used loudspeakers to inform the visitors about the possible threat.

“We hope it will continue tomorrow. Please head to the exits,” they announced.

DW’s Rick Faulker tweeted there were “many glum faces” at the scene.

The announcement on the festival’s official Facebook page states:

“Due to a terrorist threat, the police has advised the organizer from rock am ring as a precautionary measure, the festival need to interrupt provisionally, also in the event area in order to allow for investigations. This is why all the visitors were invited to leave the festival grounds, controlled and calm in the direction of outputs and campsites.
The Organiser informed on the further development, on social media, the media and radio. The organisers hope rock am ring tomorrow to be able to continue.”