Three people were killed, and four others seriously wounded in a stabbing attack at a festival in the western German city of Solingen, police said.
They said that at around 10pm (9pm Irish time) a single, unidentified man attacked multiple people.
Bild newspaper quoted witnesses as saying the perpetrator was still at large.
"It tears my heart apart that there was an attack on our city. I have tears in my eyes when I think of those we have lost. I pray for all those who are still fighting for their lives," Mayor Tim-Oliver Kurzbach said in a statement.
The police said the attack occurred at a festival to honour the town's 650th anniversary.
"There are multiple dead and injured due to a knife attack," the police said in a post on X.
Local police said they could not comment over the phone.
The attack occurred at the Fronhof, the mayor's statement said, a market square where live bands were playing.
Solingen is in North Rhine-Westphalia state, Germany's most populous and bordering the Netherlands.
Fatal stabbings and shootings in Germany are relatively uncommon.
In June, a 29-year-old policeman died after being stabbed in the German city of Mannheim during an attack on a right-wing demonstration.
There was a stabbing attack on a train in 2021, injuring several people.
The German government has been aiming to toughen rules on knives that can be carried in public by reducing the length allowed.
In shock
The Solinger Tageblatt newspaper reported that one of the co-organisers of the festival had come on stage to cancel the event.
The crowd were also asked to leave the city centre, it said.
Following the announcement, thousands of attendees cleared the area, the paper reported, with a journalist at the scene describing the atmosphere as "ghostly".
"People left the scene in shock, but calmly," Philipp Mueller, one of the organisers, told the newspaper.
A witness who spoke to the Tageblatt said he was a few metres from the attack, not far from the stage, and "understood from the expression on the singer's face that something was wrong".
"And then, a metre away from me, a person fell," said the man, Lars Breitzke, who at first thought it was someone who was drunk.
But when he turned around, he saw other people lying on the ground and several pools of blood, he added.
