London - British police said two people had been killed after a helicopter crashed into a crane on top of a residential block in central London on Wednesday.
"Two people have been confirmed dead at the scene. We have no further details," police said in a statement. Two others had been taken to hospital, it added.
The helicopter crashed just south of the River Thames near the Underground and mainline train station at Vauxhall, and British spy agency, MI6.
A photo shown on Sky News showed wreckage burning in a street, and a large plume of black smoke was seen rising in the area. Video from the crash scene showed a line of flaming fuel and debris.
London Fire Brigade said it was called at 08:00 to a report of a crash on Wandsworth Road on the south bank of the Thames.
"There was a flash and the helicopter plunged to the ground. It exploded and you can imagine the smoke coming out of it," Paul Ferguson, an office worker near the scene, told BBC News.
Erin Rogers, who was waiting a bus stop near Vauxhall Station, said she "heard a bang and saw bits of crane debris falling to the floor".
"Then the helicopter was in flames. The rest of the people at the bus station were looking on going 'What was that?' "
Police said the helicopter appeared to have hit a crane.
Early reports indicated the crane was at St George's Wharf, a high rise apartment complex with apartments that offer sweeping river and city views.
The area, roughly ten blocks from the major Waterloo train and Underground station, is extremely congested during the morning rush hour. Many commuters arrive at the main line stations from London's southern suburbs and transfer to busses or trains there.
"There are tons of emergency services about, and it looks like a helicopter hit a crane of one of the apartment buildings being constructed round there," said Jon Hoeksma, a local businessman.