Five people have been injured, two seriously, in an attack by a man armed with a chainsaw 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.
The police say the attack is not related to terrorism.
Local shops are shut, and people have been told to avoid the area.
The police say the alarm was raised at 10:39 local time (08:39 GMT), when an armed man was reported to have entered office buildings in Schaffhausen.
At a news conference, police said the attacker was on the run, and a large number of officers had been deployed in the area.
They confirmed they knew who the attacker was, describing the man as being about 190cm (6.2ft) tall, with an unkempt appearance. He is believed to be driving a white VW van.
Schaffhausen is the capital of the Swiss canton with the same name.
About 36,000 people live in the historic town.