An attacker with a knife killed three people and seriously wounded at least five late Friday at a festival in the western German city of Solingen, authorities said.

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

They said they believe the stabbings were carried out by a lone attacker.

One of the festival organizers, Philipp Müller, appeared on stage and asked festivalgoers 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.”

At least one helicopter was seen in the air, while many police and emergency vehicles with flashing blue lights were on the road and several streets were closed off.Police put the number of seriously injured at five. The region’s top security official, Herbert Reul, gave a figure of six as he visited the scene in the early hours of Saturday.

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