At least six people were killed and several others injured after a bus caught fire Tuesday evening (local time) in the town of Kerzers, known in French as Chiètres, in Fribourg canton in western Switzerland, police said.Emergency services launched a major rescue operation at the scene, with local media reporting that a helicopter had been deployed to assist responders. The cause of the blaze was not immediately known. Video shared by local media showed the bus engulfed in flames, while a resident reported seeing a thick column of smoke rising from the area.The TOI could not verify the authenticity of the video.