Two people have died and several were injured when a helicopter crashed in central London after the pilot attempted to divert due to bad weather.

The helicopter spun out of control and crash-landed after clipping a crane on top of one of Europe's tallest residential towers. It fell from the sky before exploding into flames, plunging on to Wandsworth Road near Vauxhall station.

The owners of London Heliport at Battersea said they received a request via Heathrow air traffic control from the pilot asking to divert due to bad weather. Police said the helicopter was on a scheduled flight from Redhill, Surrey, to Elstree, Hertfordshire.

The two people killed were the pilot and someone on the ground, emergency services said. Firefighters rescued a man from a burning car and brought a blaze caused by the crash under control. London Ambulance Service said 57 firefighters and officers were attending a crane which has been left in a precarious position at St George Wharf as a result of the crash.

Metropolitan Police Commissioner Sir Bernard Hogan-Howe said: "Two people have been confirmed dead. One of those has been identified as the pilot of the helicopter."The second fatality has yet to be identified, he said. He did not name the deceased. He said 60 officers were at the scene and there were extensive road closures in place.

London Ambulance Service said 12 people were injured. A spokesman said: "We have treated five patients - four for minor injuries and one patient for a broken leg. Three of the patients were taken to St Thomas' Hospital and two - a man and a woman in their 50s - were taken to King's College Hospital. Seven patients were treated at the scene." A spokesman for King's College Hospital said the two patients had been discharged and left the hospital. Pauline Cranmer, from the service, said: "There were a number of injuries that would potentially be consistent with being hit by debris. Our primary concern is about treating the injuries." She said the two fatalities were pronounced dead at the scene by air ambulance crews.

Addressing a press conference near the scene of the incident, Commander Neil Basu, of the Metropolitan Police, said the force was working with other agencies including the Air Accidents Investigation Branch and the Civilian Aviation Authority. Asked if the lights on top of the building and crane were faulty, Mr Basu said: "That will form part of the investigation."

The crane was on top of a building called The Tower in the St George Wharf development. A spokesman for Berkeley Group, which owns St George, the development company for the building, said in a statement: "Our thoughts at this time are with the friends and families of those killed in this tragic incident." There was traffic chaos in the wake of the incident, with Vauxhall Bridge Road southbound closed, Wandsworth Road partially closed, Nine Elms Lane partially closed and South Lambeth Road partially closed. Vauxhall Tube, railway and bus stations were also closed.

The aircraft is understood to be an AgustaWestland AW109, a lightweight, twin-engine helicopter with eight seats. Castle Air Charters, based in Liskeard, Cornwall, refused to comment on reports that the helicopter is registered to the company. A spokeswoman said they would be releasing a statement later. The company specialises in chartered helicopter flights across the county and many of its aircraft are also used in London.

It is understood there were lights in place on top of the crane, which were checked twice a day and had been checked on Tuesday. There had been confusion over whether the lights had been functioning correctly, but it looks increasingly likely they were obscured by the thick mist shrouding the tower. Cloud in central London was very low at the time of the accident, which happened at around 8am, weather forecasters said. Paul Knightley, of MeteoGroup, the weather division of the Press Association, said London City Airport was reporting a cloudbase of just 100ft (30.5m) at 8am. The top of the building would have been shrouded in cloud, he said.