A terrorist incident has been declared at Parsons Green underground station in west London after an explosion on a tube carriage.
The Metropolitan police and British Transport Police (BTP), including armed officers, are at the scene, along with the London ambulance service (LAS).
The Met’s assistant commissioner Mark Rowley said a suspected improvised explosive device (IED) was thought to be responsible for the blast. Scotland Yard said no one has yet been arrested
Police sources said the device only partially exploded. Initial examination by explosives experts led them to conclude it was “viable”, meaning the device was meant to explode more fully. A circuit board was recovered from the scene.
A massive search is under way for whoever planted the homemade device. Detectives are examining CCTV from the London Underground network to determine where the perpetrator entered and exited the tube system.
Scotland Yard’s counter-terrorism command, SO15, has taken the lead in the investigation, supported by MI5. The inquiry into the explosion was initially led by BTP.
St Mary’s hospital in Paddington, central London, has declared a major incident, and there have been reports of people sustaining burns. Guy’s and St Thomas’ NHS foundation trust also declared a major incident.
LAS said it had taken 19 people to a number of London hospitals. “None are thought to be in a serious or life-threatening condition,” a statement said. Three others went to hospitals independently.
One witness, Sham Shakil, told the BBC he saw several people “falling over themselves” as they tried to get out of Parsons Green station.
Another passenger, named only as 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.”
The BBC journalist Sophie Raworth said: “I have just seen a woman who was just stretchered off here and clearly her legs are wrapped up, and she has burns. She had burns to her face; she’s conscious, she was taking oxygen and pain relief as well. She seemed to have burns all over her body from top to toe.”
Chris Wildish, who was on the train, said he saw a device in the last carriage: “It was a white bucket, a builder’s bucket, in a white Aldi bag or Lidl bag. Flames were still coming out of it when I saw it and [it] had a lot of wires hanging out of it … It was standing against the door of the rear-most carriage.”
Police have advised people to avoid the area and a 100-metre (330ft) cordon has been erected around the station.
London fire brigade said it had six engines, two rescue units and about 50 firefighters from Fulham, Wandsworth, Chelsea, Hammersmith and other surrounding fire stations at the scene.
A Transport for London spokeswoman said the District line had been suspended between Earl’s Court and Wimbledon.
Downing Street said the prime minister, Theresa May, was to chair a meeting of the government’s Cobra emergency committee on Friday afternoon to discuss the incident. In a statement, May said: “My thoughts are with those injured at Parsons Green and the emergency services who, once again, are responding swiftly and bravely to a suspected terrorist incident.”