Here’s everything that is known so far about the Parsons Green incident so far.
Emergency services were called to a London Underground station at 08:20 BST (07:20 GMT) on Friday after reports of an explosion on a train bound for central London.
Images show an explosion in a bucket towards the rear of a train at Parsons Green Tube station. A “major incident” has been declared by the British Transport Police and Scotland Yard’s counter terrorism command, S0 15, has taken the lead in the investigation.
READ MORE: Parsons Green: London Tube commuters injured in explosion
London Fire Brigade said it has sent six fire engines and 50 firefighters to the incident.
A witness said there were injuries after a “stampede” of passsengers. BBC news reader Sophie Raworth said she had seen a woman with burns “from top to toe” being stretchered into an ambulance. Parsons Green is in West London on the District Line. Major tube stations including Westminster, Victoria and Embankment are further along the line
In a statement, Scotland Yard said: “Police were called at approximately 8.20am to Parsons Green Underground Station following reports of an incident on a Tube train. “Officers from the Metropolitan Police Service and British Transport Police are in attendance along with the London Fire Brigade and London Ambulance Service. The Metropolitan Police said: “We are aware of an incident at Parsons Green Tube station. Officers are in attendance.” British Transport Police said: “We’re aware of an incident at Parsons Green station. Officers are at the scene. The station is closed.”
A passenger called Lucas said: “I heard a really loud explosion – when I looked back there appeared to be a bag but I don’t know if it’s associated with it. “I saw people with minor injuries, burnings to the face, arms, legs, multiple casualties in that way. People were helping each other.
Nicole Linnell, 29, who works for a fashion label, said: “We saw people running down the tracks. About 30 or 40 people.
“They were running down the tracks outside our train.
“It was absolutely terrifying. Running on the tracks is the last thing you want to do so we were like ‘What’s going on?’
“After about an hour we were evacuated off the train on to the tracks. About 10 to 15 people at a time.”
Sylvain Pennec, a software developer from Southfields, near Wimbledon, was around 10 metres from the source of the explosion when fire filled the carriage. “I heard a boom and when I looked there were flames all around,” he said.
“People started to run but we were lucky to be stopping at Parsons Green as the door started to open.”
He described the scene of panic as commuters struggled to escape the carriage, “collapsing and pushing” each other.
Mr Pennec stayed behind to take a closer look at what he believed was the source of the explosion. “It looked like a bucket of mayonnaise,” he said. “I’m not sure if it was a chemical reaction or something else, but it looked home made. I’m not an expert though.”
Media technology consultant Richard Aylmer-Hall, 53, was sitting on the District Line train bound for central London when panic unfolded at around 8.20am. 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.”
Boris Johnson: Keep calm
Boris Johnson told Sky News: I’m afraid my information is limited and it really is important not to speculate at the moment. “Everybody should keep calm and go about their lives in as normal a way as they possible can. The British Transport Police, TFL are on it. And they will be updating their websites as and when we get more information.