Police in Germany have evacuated the Rock Am Ring music festival after receiving a terror threat. The major event was cleared out on Friday evening after police in the nearby city of Koblenz said they had received information about a "concrete threat". "Due to a terrorist threat the police have advised us to interrupt the festival,” organisers said on the festival website. Around 90,000 music fans were expected to attend the annual three-day event by the end of the weekend. The German band Rammstein was the Friday night headliner, but hadn't yet started playing. Festival organisers say they hope to be able to go ahead with the programme Saturday. Festival-goers were told to move to the camping area after being told of the evacuation.