People were killed and injured in an attack at the 650th anniversary celebrations of the city of Solingen in western Germany, according to the police late on Friday evening.
Police sources said a knife was likely involved.
Armed officers are currently at the scene and have cordoned off large areas of the city and set up privacy screens.
The incident took place in Fronhof, a marketplace in the city centre where a stage was set up for live music.
Thousands of people were leaving the area, after the authorities called on residents to remain calm and go home, the local Solinger Tageblatt newspaper reported.
The festival was temporarily suspended and sirens could be heard around the city centre. There were helicopters overhead and ambulances at the scene.
Philipp Müller, one of the co-organizers of the event, said on stage according to the report that paramedics are fighting to save the lives of nine people.
The event, a Festival of Diversity, began on Friday to mark the 650th anniversary of the city of Solingen and was due to continue through to Sunday.
The city centre was set to become a large festival mile according to posters ahead of the event that promised music, cabaret, acrobatics, arts and crafts, entertainment for children and more.
