Two trapped passengers have now been rescued from the top deck of a London bus which crashed into a kitchen shop on a busy high street today, sparking morning rush hour chaos in the UK capital.

Police said there were "casualties" after the crash in South West London, with two fire engines and three fire rescue units sent to the scene.

Firefighters with cutting gear had been trying to rescue two women trapped on the top deck of the bus, but added that the passengers were 'both conscious and breathing'.

Paramedics said they had treated six patients and remain on scene. Officers were called just before 7am (6pm New Zealand time) to reports of a bus hitting a building.

Glass could be seen shattered across the ground and paramedics were tending to people on the top deck of the number 77 double-decker bus.

Police said paramedics had treated "a number of passengers" and the bus driver had been taken to a hospital in South London.

Local resident Brendan Pfahlert said the smash near the commuter hub of Clapham Junction train station "sounded like a large amount of glass being dropped'"

In total, nine people suffered minor injuries when the bus hit the building near Clapham Junction railway station in southwest London.

One passenger claims the driver said he "blacked out" before the crash.