BERLIN (AP) – German authorities are considering whether to let a popular rock festival go ahead after its opening night was curtailed amid concerns over a possible terrorist threat.

The top security official in western Rhineland-Palatinate, Roger Lewentz, planned a news conference at 11 a.m. (0900 GMT) Saturday after authorities shut down and cleared thousands of fans from the three-day Rock am Ring festival Friday night.

The site was calm overnight. Police said they were continuing a search of the grounds on Saturday morning.

Authorities didn’t give details Friday night of what they called “concrete indications on the basis of which a possible terrorist threat can’t be ruled out.”

Following the recent attack in Manchester outside a concert, authorities had put a strong police presence in place.

UPDATE: The festival is now going ahead. The organiser said his event was “paying the price” for officials’ failure to prevent the December attack on a Christmas market in Berlin.