KERZERS, Mar 11 (AFP): A bus caught fire in western Switzerland on Tuesday killing at least six people and injuring five others in what police said may have been a deliberate act.
The fire broke out on the bus in the main street of the small town of Kerzers, around 20 kilometres (12 miles) west of the Swiss capital Bern, at about 6:25 pm (1725 GMT).
Videos circulating on social media showed flames several metres high bursting out from the windows, and black smoke rising into the sky.
The fire "left at least six dead and five injured, three of them seriously", Fribourg cantonal police spokesman Frederic Papaux told AFP.
"The police are currently treating the fire as a man-made incident, and even a deliberate act," he said, without providing further details.
At a press conference, police would not be drawn on potential hypotheses including suicide or an act of terror.
"There were no other vehicles involved-only the bus. And that bus caught fire... we are currently trying to determine the precise reason why this happened," Papaux told reporters.
He could not say how many people were on the bus at the time, adding that panicked and injured passengers were getting out when first responders arrived.
"Emergency services rushed to the scene and found the vehicle completely engulfed in flames. Firefighters carried out rescue and extinguishing operations. A security perimeter was set up," a police statement said.
Several ambulances and a helicopter were sent to the scene and three injured people were taken to hospital. Two other people were examined on site but did not need hospital treatment.
A hotline has been opened for witnesses to come forward, as the authorities try to determine the exact circumstances of the fire. Fribourg police said a criminal investigation had been opened by public prosecutors.
"At this time, we know the identities of the injured. If the appeal for witnesses leads us to identify others, it will allow us to move forward with the investigation," said Papaux.
"As for the on-site investigation, it will require several hours of work. You may have seen the state the bus is in."
The burnt-out shell of the bus was screened off behind white tarpaulins set up across the road, an AFP journalist saw. The scene was cordoned off, with police standing guard at the tape. Firefighters and fire trucks were also present.
Police appealed to the general public to stay away from the area. It is the second major multiple-casualty fire in Switzerland in less than three months.
In the early hours of January 1, a bar in the ski resort of Crans-Montana caught fire as people celebrated the New Year. A total of 41 people died, with another 115 injured.