Police have cordoned off Abingdon Street today (June 11) at 1.29pm after the crash involving a coach and a pedestrian.
An air ambulance was recorded landing near Parliament Square and a man has been taken to hospital.
His condition is unknown at this time, but the London Ambulance Service has said medics are treating him for a head injury.
No arrests have been made following the crash.
Separately, another police cordon is in place just minutes away at the southern end of Whitehall.
Officers are investigating an abandoned vehicle due to its vicinity near Downing Street.
It is not being treated as linked as the separate crash in Abingdon Street.
A Metropolitan Police spokesperson said: “Officers were called to reports of a road traffic collision involving a coach and a pedestrian at 13:29hrs on Wednesday, 11 June on Abingdon Street, Westminster.
“Officers, the London Ambulance Service, London’s Air Ambulance, and the London Fire Brigade attended and a man was taken to hospital. We await an update on his condition.
“Road closures are currently in place.
“No arrests have been made.”