BLASTS ON TUBES AND BUS
According to reports a bus has exploded in central London just minutes after a number of blasts on London's Underground.
"I saw lots of people running up a road and then saw the top of a bus destroyed," one eyewitness told Sky News.
Sky News producer Bob Mills said he heard the loud explosion near Euston Station.
The entire Tube network has been shut down following the blasts at Aldgate, Edgware Road, King's Cross, Old Street and Russell Square.
It is understood several people have been wounded in the underground blasts, with one unconfirmed eyewitness telling Sky News he saw "bodies on the line".
British Transport Police confirmed there are "walking wounded" and said paramedics have responded to one report of a person classed as "life at risk".
"It's chaos, with people trying to work out what has happened," said a spokesman.
One witness said the packed underground train he was on was 200 metres from King's Cross when there was a huge flash.
The train stopped and people were using umberellas to smash windows of the trains. Passengers were led out of the train by underground staff.
He added people were milling around King's Cross covered in soot.
Clare Benson, 33, a city banker from Kensington, was on a tube at Edware Road where the second incident took place.
"I was in the last carriage at the back of the train nearest the tunnel when I heard a huge bang - you could feel it," she said.
"The lights went off for a couple of minutes and people were scared and wondering what to do.
"The drivers got out and were looking into the tunnel, then they announced that we should evacuate. My ears are still ringing and I was shaking."
Several hurt in Tube 'explosion'
Several people have been injured after explosions blamed on a power surge led to the whole London Underground network being closed down until further notice.
British Transport Police said some of the power surges had caused explosions.
'Screaming and crying'
Jacqui Head, from BBC News, who had just left King's Cross station on a Piccadilly Line train as an explosion happened, said: "Everything was normal. Suddenly there was a massive bang, the train jolted.
"There was immediately smoke everywhere and it was hot and everybody panicked. People started screaming and crying."
The train was kept in the tunnel for 20 minutes and no announcement was made to explain the delay to passengers, she added.
London Fire Brigade said four crews were at Liverpool Street and more were on their way.
Another passenger, who had left the Tube at Fenchurch Street Station, and walked to Aldgate East, told BBC Five Live that he saw injured people.
"As I walked through the bus station I could see people lying on the ground, black, as if they'd been covered in smoke. There were about three or four people on the floor being treated."
Eyewitness Paul Woloszyn from BBC News, who was at Blackhorse Road station on the Victoria Line, said: "We were told there was a bomb at Liverpool Street station.
"I was on the Tube, and they stopped the train and told everyone to get off and evacuate the station."
He said staff had said the entire Tube network had been affected, and leaflets had been handed out with details of alternative bus routes.
Another eyewitness, Dorothy Molloy, had been on a Tube train at King's Cross and said "staff just chucked everyone out of the station".
She said staff there had not given any details, but she said two passengers she had spoken to had said they had received messages saying there had been bombs.
"People didn't really know what was going on, they were just huffing and puffing and saying how annoying it was," she said.
"People don't seem to be panicked, but there's so many police and ambulances coming into the areas. People are just concerned, and some are just annoyed at the dela
A City of London Police spokesman said there were "quite a large number of casualties" at Aldgate Station.
A bus was ripped apart in an explosion in central London, an eyewitness told news agency PA, and there were reports of at least one fatality.
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.
The National Grid, which supplies power to the Underground, said there had been no problems with its system which could have contributed to the incidents.