Police evacuated some 80,000 people at a three-day rock festival in far west Germany late Friday because of "concrete evidence" of a possible terrorist threat, authorities said.

Festivalgoers were instructed to leave the Nuerburgring arena outside Nuerburg and go to nearby camping sites, according to organizers of the event, called Rock-am-Ring. The festival was expected to resume on Saturday.

The German band Rammstein was headlining Friday night but had not yet taken the stage. Police said the crowd streamed to the exits in an orderly fashion.

The music fest, which is scheduled to end on Sunday, was taking place at an outdoor sports arena near Nuerburg, in the state of
Rhineland-Palatinate, about 35 miles south of Bonn and close to the Belgian border.

"Since safety is paramount and a danger to festivalgoers in any case must be excluded as much as possible, it was decided to suspend the festival for the day," Koblenz police said in a statement.

They added that police had "concrete evidence" of a possible terrorist threat, but did not elaborate.

Police said security was particularly high at the event because of last week's suicide bomb attack at an Ariana Grande concert in Manchester, England, that killed 22 people.

Security at the Rock am Ring event was beefed up to around 1,200 personnel, police said..