man is fighting for his life after being stabbed on a double-decker bus on Oxford Street.
Police said the victim, 25, was attacked on board the bus as it made its way down the famous central London Street at 10.20pm on Tuesday.
He was found with critical injuries and taken to hospital where he remains in a life-threatening condition.
The tourist hotspot is cordoned off next to John Lewis with a 94 bus parked at the scene.
Images from the scene show a pool of blood on the pavement next to discarded first aid equipment.
No arrests have been made so far.
A Met spokesman said: “Police were called to reports of a man stabbed on board a bus on Oxford Street.
“Officers attended and found a 25-year-old man critically injured. He was taken to hospital by the London Ambulance Service where he remains with life-threatening injuries.
“A crime scene is in place and parts of Oxford Street remain closed to traffic.
“Additional officers are in the area.”
Anyone with information is asked to call police via 101 quoting reference CAD 7103/28Feb.