LONDON, United Kingdom - Passengers were seen "badly burned" following a possible explosion on a London Underground train, eyewitnesses said Friday as emergency services confirmed they were responding to an "incident".
Witnesses reported seeing passengers who had suffered facial burns and had hair coming off, with at least two women seen being treated by medics amid scenes of panic during rush hour.
"Explosion on Parsons Green District Line train. Fireball flew down carriage and we just jumped out open door," said Twitter user @Rrigs, who posted pictures of a white bucket smouldering on the train.
The bucket looked like the type used by builders and there appeared to be cables coming out of it.
"We are aware of an incident at Parsons Green tube station. Officers are in attendance," London's Metropolitan Police said on Twitter.
The station was closed, as well as an entire section of the District Line where it is located, and police urged people to stay away from the area.
A Metro.co.uk reporter at the scene was quoted by the paper as saying that some passengers were "really badly burned" and their "hair was coming off".
The incident comes after a series of terror attacks that have rocked Britain this year, killing dozens of people and injuring hundreds, putting the capital on high alert.
British Foreign Secretary and former London mayor Boris Johnson appealed for calm.
"I'm afraid my information is limited and it really is important not to speculate at the moment," he told Sky News.
"Obviously, everybody should keep calm and go about their lives in a normal way, as normal as they possibly can," he said.
'Covered in blood'
Passengers described chaotic scenes at the station in a leafy and normally quiet part of west London.
"There was panic, lots of people shouting, screaming, lots of screaming," Richard Aylmer-Hall, 52, a media technology consultant, told the Press Association.
"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," he said, adding that "some people got pushed over and trampled on.
"I saw two women being treated by ambulance crews," he said.
BBC correspondent Riz Lateef, who was on her way 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."
One passenger, named only as Lucas, told BBC 5 Live radio: "I heard a really loud explosion".
"I saw people with minor injuries, burnings to the face, arms, legs, multiple casualties," he said.
Another witness, Sham, told the radio station he had seen a man with blood all over his face.
"There were a lot of people limping and covered in blood," he said.
Emergency services said they were called at around 8:20 am (0720 GMT).
Natasha Wills, assistant director of operations at London Ambulance Service said: "Our initial priority is to assess the level and nature of injuries".
She said the ambulance service had sent "multiple resources" to the station, including a hazardous area response team.