'I was blissfully reading my paper... suddenly the whole world charged past me' - witness
A witness to a "fireball" on London's Underground has described the panic on the train following an explosion.
Media technology consultant Richard Aylmer-Hall, 53, was sitting on the District Line train bound for central London this morning when panic unfolded at around 8.20am after a reported blast on a train.
He said he saw several people injured, having apparently been trampled as they tried to escape.
He told the Press Association: "I was blissfully reading my paper and listening to a podcast and suddenly the whole world charged past me down the platform, down the Tube.
"I was on the Tube, we had just stopped at Parsons Green, I was on my way up from Wimbledon towards Paddington and suddenly there was panic, lots of people shouting, screaming, lots of screaming.
"There was a woman on the platform who said she had seen a bag, a flash and a bang, so obviously something had gone off.
"It was an absolutely packed, rush-hour District Line train from Wimbledon to Edgware Road.
"I saw crying women, there was lots of shouting and screaming, there was a bit of a crush on the stairs going down to the streets.
"Some people got pushed over and trampled on, I saw two women being treated by ambulance crews.
"Since then, every emergency vehicle in London has gone past me, fire engines, ambulances, every type of police vehicle."
Mr Aylmer-Hall added: "I don't think anyone was hurt by the actual device or whatever it was."
Outside the station, a woman was sitting on a pavement with a bandage around her leg while armed police patrolled. A Reuters witness saw a woman being carried off on a stretcher with her legs covered in a foil blanket.
BBC correspondent Riz Lateef, who was at the station travelling to work, said there was "panic as people rushed from the train, hearing what appeared to be an explosion.
"People were left with cuts and grazes from trying to flee the scene. There was lots of panic," she said.
A woman has described how she kept running with the crowd, despite not knowing what had happened on the train.
Teacher Sally Faulding told BBC News her colleague told her she heard a "whoosh" sound before seeing flames coming towards her.
"I was in the middle of the train.
"Suddenly I saw people coming towards me.
"I didn't know what was going on but I knew something was wrong because of the volume of people coming towards me.
"The doors opened and I just ran out as everyone else did.
"We were still running on the platform and people were falling down, trying to make an exit.
"I fell over someone who fell in front of me," Ms Faulding continued.
"I kept on running even though I still didn't know what I was running from.
"Basically we moved out of the station. People were crying, visibly upset.
"I then heard people saying that there had been an explosion, a fire."
Ms Faulding said she bumped into a colleague of hers who confirmed she had seen a fire.
"She said she saw a surge of fire coming toward her.
"She heard a whoosh sound before that.
"I saw a man who had burns on his arms and a woman who had her hair singed."
British authorities are treating an incident at a London metro station as terrorism.
Prime Minister Theresa May is "getting regular updates" according to her office.
Scotland Yard has said there was an explosion on the train as a result of an IED device on board the tube.
Mark Rowley, Assistant Commissioner for Specialist Operations of the Metropolitan Police, says police are being supported by counter intelligence colleagues from MI5 and has reassured Londoners there will be an increased police presence in the city after the incident.
London Ambulance Service confirmed 18 people have been brought to hospital following the explosion and none are thought to be in a life-threatening or serious condition.
Mr Rowley said it was understood that "most" of the 18 injured were suffering from "flash burns".
Police are now advising people to avoid the area.