Eight were injured, five of them seriously, the police said in a statement. That is up from fewer serious injuries the police reported earlier.

“Both victims and witnesses are currently being questioned. The police are currently searching for the perpetrator with a large team,” police said.

The news agency dpa cited unidentified police sources as saying the weapon used was believed to be a knife.

The “Festival of Diversity” marking the city’s 650th anniversary began on Friday and was supposed to run all weekend, with several stages in central streets offering attractions such as live music, cabaret and acrobatics. The rest of the festival has been cancelled.

Solingen has about 160,000 inhabitants and is located near the bigger cities of Cologne and Duesseldorf.

One of the festival organisers, Philipp Müller, appeared on stage and asked the audience to “go calmly; please keep your eyes open because unfortunately the perpetrator hasn’t been caught”. He said many people had been wounded by “a knifeman”.

Mayor Tim Kurzbach said in a Facebook post that “this evening, we in Solingen are all in shock. We all wanted to celebrate our city’s anniversary together and now have dead and wounded to lament.”

“It breaks my heart that an attack on our city happened,” he added.

Newspaper Solinger Tageblatt quoted Celine Derikartz, its reporter covering the festival, as saying that “the atmosphere is spooky”. She said a party atmosphere had turned to shock within minutes and she saw festival goers weeping.

Germany’s top security official, Interior Minister Nancy Faeser, recently proposed toughening weapons laws to allow only knives with a blade measuring up to 6 centimetres to be carried in public, rather than the length of 12 centimetres.

There has been concern about an increase in knife violence in Germany recently.

In May, a knife attack by an Afghan immigrant on members of a group that describes itself as opposing “political Islam” left a police officer dead.

AP and Reuters