Update 5.58pm: A man armed with a chainsaw has wounded five people at a health insurer's office in the northern Swiss city of Schaffhausen, triggering a manhunt for a suspect described as aggressive and psychologically unstable.
Suspect Franz Wrousis, 51, has two previous convictions for weapons offences, authorities said.
The attacker wounded two insurance agency employees in their ground floor office in the old town of Schaffhausen on Monday morning, said Christina Wettstein, a spokeswoman for insurer CSS.
Authorities said their lives were not in danger.
Revising earlier statements, police said one CSS employee was seriously injured and the other was slightly injured. Another three people were slightly injured in the attack, police said.
The perpetrator had fled by the time police arrived. Authorities sealed off the city's old town until mid-afternoon as the hunt continued.
Swiss police have ruled out terrorism.
"This was first and foremost a crime against this insurance agency," senior regional police official Ravi Landolt told reporters.
"We have information that this man is dangerous, that he is aggressive and, shall we say, psychologically disturbed."
Swiss media reported that Wrousis was a CSS client. Switzerland has a system that requires residents to have mandatory health insurance with private health insurers.
Prosecutor Peter Sticher said Wrousis has two previous convictions for offences against weapons laws, one from 2014 and 2016.
He did not elaborate or say whether they were committed, but said Wrousis has no previous record in the small northern state of Schaffhausen, near the German border.
Wrousis was previously registered as living in Graubuenden, in Switzerland's south-east. He apparently lives mostly in woods, Mr Landolt said.
Police released old photos of Wrousis standing among trees in a green T-shirt and black jeans.
They described him as being about 6ft 2in, and said he is now bald and unkempt.
Police found the Volkswagen minivan with registration plates from Graubuenden that the suspect was believed to be driving.
They did not elaborate on its condition or say if anything else was found in it.
Schaffhausen is a city of about 36,000 people north of Zurich.
Therese Karrer, who often walks her dog in woods south of Schaffhausen, said she saw the suspect, who is of no fixed abode, several times in the last few weeks.
"I talked to him a few times and walked by his car every day with our dog," said Ms Karrer, who lives in the village of Uhwiesen.
She said Wrousis showed up three or four weeks ago in the forest and chatted with her once when he was having breakfast behind his car.
"He may have been a little strange, but he wasn't unfriendly," she said. "I never felt threatened."
Update 12.45pm: Swiss police have said the attack in Schaffhausen is not a terrorist act.
Earlier: Police are searching for a man after five people were injured, two of them seriously, after an apparent attack in the northern Swiss town of Schaffhausen.
A police spokeswoman said officers were alerted to the incident at 10.39am local time (9.39am BST).
She said: "We can't say exactly what happened at this point.
"We just know that a person wounded several people."
The man's whereabouts are currently unknown, and police cannot say with certainty what implement he used to injure the people involved.