At least six people have been killed and three others hospitalised with severe injures after a bus caught fire in a town west of the Swiss capital.
Police spokesperson Frederic Papaux said an unspecified deliberate act could be the cause of the fire in the town of Kerzers, about 25 kilometres west of Bern, the capital.
"At this stage, we have elements suggesting a deliberate act by a person who was inside the bus," said Papaux.
The regional transport bus is operated by PostBus, which is affiliated with the national postal service.
"After rushing to the scene, rescue teams noted that the vehicle was totally engulfed in flames," the regional government said in a statement.
Ambulance and helicopter teams ferried three injured people with severe injuries to hospitals, while two others were treated on site, a police statement said.
Papaux said at least six people were killed in the fire on Tuesday night, local time. An investigation is under way.
With Reuters