At least six people have been killed and others injured after a bus caught fire in a town in western Switzerland, according to police.

The incident took place on Tuesday evening in Kerzers - known in French as Chiètres - in Fribourg canton, about 20km (12 miles) from the capital, Bern.

A major rescue operation is under way and local media reported a helicopter had been deployed.

The cause of the fire is not yet known.

Video posted by local media shows a bus in flames and a local resident mentioned seeing a thick column of smoke.