Five people have been injured, two seriously, in an attack by an unidentified man in the Swiss town of Schaffhausen, police say.
Central parts of the town on the German border have been sealed off, as police are searching for the attacker.
Police and ambulances are on the scene and rescue helicopters are circling overhead, police spokeswoman Cindy Beer is quoted as saying by Swissinfo.
Local shops are shut, and people have been told to avoid the area.
The police say they first received reports of the attack at 10:39 local time (08:39 GMT), and deployed in large numbers.
At a news conference later on Monday, the police said the attacker was on the run.
Unconfirmed reports say he was armed with a chainsaw.
Schaffhausen is the capital of the Swiss canton with the same name.
About 36,000 people live in the historic town.