London Sub Explosion - Many Casualties at Aldgate Station

The following report from BBC World:

Several people have been injured after explosions on the Underground network and a double-decker bus in London.

A police spokesman said there were "quite a large number of casualties" at Aldgate Tube Station.

And Scotland Yard confirmed one of several reports of explosions on buses in the city - in Tavistock Place - but said the cause was not yet known.

One caller to BBC Five said his friend had seen "the bus ripped open like a can of sardines and bodies everywhere."

PA also quoted union officials as saying sources had told them there had been at least one explosive device on the Underground. British Transport Police Surges took place at Aldgate, Edgware Road, King's Cross, Old Street and Russell Square stations.

Scotland Yard confirmed they were assisting with a "major incident" and said there were casualties.

A spokesman said officers were called out to Aldgate station at 8.50am to assist City of London and British Transport Police.

"All of the emergency services are on scene. There have been some casualties. This has been declared as a major incident," said the spokesman. "It's too early to state what has happened at this stage," he said.