SOLINGEN, Germany (AP) — A large-scale search was underway Saturday in the western German city of Solingen after three people were killed and at least eight people wounded, five of them seriously, in a knife attack at a festival.

“The police are currently conducting a large-scale search for the perpetrator,” police said in a statement. They have assembled a large number of forces around Solingen city center, including special units. “Both victims and witnesses are currently being questioned,” they said.

Witnesses alerted police shortly after 9:30 p.m. Friday to an unknown attacker having wounded several people with a knife on a central square, the Fronhof. Police said that the perpetrator was on the run, and that they so far had only very thin information on the assailant.

They said they believe the stabbings were carried out by a lone attacker and gave no information about the identities of the victims.

The “Festival of Diversity,” marking the city’s 650th anniversary, began Friday and was supposed to run through Sunday, with several stages in central streets offering attractions such as live music, cabaret and acrobatics.

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

“We are deeply shocked by the brutal attack on the city festival in Solingen,” German Interior Minister Nancy Faeser said in a statement Saturday morning. “Our security authorities are doing everything they can to catch the perpetrator and establish the background to the attack.”

There has been concern about increased knife violence in Germany, and Faeser recently proposed toughening weapons laws to allow only knives with a blade measuring up to 6 centimeters (nearly 2.4 inches) to be carried in public, rather than the length of 12 centimeters (4.7 inches) that is currently allowed.