GENEVA: At least six people were killed and five others injured after a fire broke out on a postal bus on Tuesday evening in Kerzers, in the canton of Fribourg in western Switzerland, cantonal police said at a press conference.

Among the injured, including one rescuer, three were reported to be in serious condition.

Police said no other vehicle was involved in the incident and added that a human cause was likely. “A deliberate act could be the cause,” the police said.