Fribourg canton’s public prosecutor Raphael Bourquin said the man allegedly responsible for the fire likely died.

At least six people have died after a bus fire that authorities say may have been caused by a man who set himself on fire in a small Swiss town.

The incident, which also injured five people, took place on Tuesday near the centre of Kerzers, a town in the western canton of Fribourg, about 12 miles (20km) from the capital Bern, police said.

According to Fribourg canton’s public prosecutor Raphael Bourquin, the man allegedly responsible for the fire was likely among those who died .

“A witness statement indicated that a man … of Swiss origin boarded the bus carrying bags. At some point, he doused himself with a flammable substance and set himself alight,” Bourquin told a news conference on Wednesday.

“There is absolutely no evidence to suggest that this could be a terrorist act,” he said, adding that the family of the man, who was from Bern canton and in his sixties, had recently “reported his disappearance”, and “current evidence describes him as a marginalised and disturbed individual”.

According to Swiss authorities, the victims of the blaze were aged between 17 and 65.

In a statement, the cantonal police said three of the injured were taken to hospitals while two were treated at the scene. Two of those admitted to hospital remained in the hospital on Wednesday, while one was discharged on Tuesday.

According to the first findings of the police investigation, the statement said, a person boarded the bus in the nearby town of Duedingen at around 5.45 pm CET (16:45 GMT) and later set himself on fire in Kerzers at about 6.25 pm local time, causing the blaze to spread throughout the vehicle.

Police said initial hearings and witness testimony indicate that the incident was “a voluntary act without ideological motivation.”

Swiss President Guy Parmelin wrote on X on Tuesday night that the fire “distresses and saddens” him.

“The circumstances are being investigated. To the relatives of the deceased from Kerzers, I extend my condolences. And I think of the injured and the rescue workers,” he said.

Zeynel Teke, 61, who was working at his food stall opposite the bus when it was engulfed in flames, said that while he went to get his fire extinguisher to put out the flames, it was too hot to get close enough.

“It’s so sad to see people burning in front of your eyes. It could be my child, it could be yours,” he told the Reuters news agency.

Officials explained that investigators were reviewing social media footage and CCTV to understand the motives behind the man’s actions, and that interviews were expected to take place.

A hotline has also been opened for witnesses to come forward, and Fribourg police said that public prosecutors had opened a criminal investigation.

The incident is the second time this year that a fire has killed many people, after a blaze in a bar in the Swiss ski resort of Crans-Montana killed 41 people and injured 115 others in January.