A helicopter has crashed in central London after apparently hitting a crane on top of a building, Scotland Yard said.
Emergency services were called to the scene, near the River Thames at Vauxhall, after reports that the aircraft had hit a crane and cartwheeled before bursting into flames.
A plume of smoke billowed into the sky above the area this morning.
Fire and rescue services said they were taking "lots of emergency calls" as eyewitnesses described seeing grey smoke towering into the sky, close to Battersea Bridge, in Vauxhall.
Eyewitnesses took to Twitter to report details. One said the helicopter appeared to have hit a crane. Another said it crashed close to a railway line. One user posted a dramatic photograph showing burning wreckage in the road.
Some eyewitnesses said the helicopter appeared to have hit a crane on a newly built tower block on the south bank of the Thames at Vauxhall Cross. It is thought the helicopter may have hit two cars. There were also reports that there was only one person in the helicopter.
A spokesman for London Fire Brigade said: "We were called at 8am this morning to a report of a helicopter crash on Wandsworth Road, south London, and we are attending."
Video footage shot on a mobile phone showed an entire road blocked by burning wreckage and aviation fuel. The side of a building on one side of the street was also damaged by the flames. Passers-by stood watching as the wreckage burned. A motorcycle was also lying on its side in the road having been abandoned. One eyewitness reported seeing cars on fire and hearing people screaming.
As rush-hour traffic built up, the A3036 Wandsworth Road in Vauxhall was closed in both directions between Vauxhall Cross and the Lansdowne Way junction. People took to Twitter to report gridlocked traffic in the area, with emergency services struggling to get through. The First Capital Connect train company warned its passengers to expect travel difficulties in the Vauxhall area, although its services were not affected.
Flying conditions this morning were reflected in the fact that London City Airport in Docklands had delays due to poor visibility.