San Francisco police said one person was injured in a stabbing on a Muni bus Monday evening.
The stabbing was reported just before 5 p.m., near Geary Boulevard and 14th Avenue.
Police said witnesses told them they had seen a man suffering from a stab wound. The victim received first aid and was taken to a hospital with life-threatening injuries.
There was no information about a suspect and police said no arrest had been made.
Anyone with information is asked to call police at 415-575-4444.
