Detectives from the Roads and Transport Policing Command are appealing for witnesses following a serious collision in Westminster.
Police were called by the London Ambulance Service at 16:43hrs on Friday, 25 November to reports of a Route 46 bus in collision with a female pedestrian on the crossing at Warwick Avenue junction with Clifton Gardens, Westminster.
Officers, London Ambulance Service and the London Fire Brigade attended.
The pedestrian, believed to be aged in her mid-20s, was taken to a central London hospital where her condition is described as critical.
Local road closures have now been lifted.
Enquiries are ongoing. No arrests.
Detectives from the Serious Collision Investigation Unit are investigating.
Anyone with information on the collision should contact the witness appeal line on 020 8543 5157.