LONDON: The London underground train blast that injured 22 people on Friday (Sep 15) is being treated as terrorism, said British police.
"At 8.20am this morning at Parsons Green station, there was an explosion on a tube train. We now assess that this was a detonation of an improvised explosive device," police counter-terror chief Mark Rowley told reporters.
Fire rescue and ambulance services also said they were notified of the incident in west London at 8.20am. The station was closed, as well as an entire section of the District Line where it is located.
A Metro reporter was quoted by the paper as saying that a white container exploded on the train and passengers had suffered facial burns. She said they were "really badly burned" and that their "hair was coming off".
Several Twitter users have also posted pictures of a white bucket smouldering on a train.
Police said they were aware of reports on social media and would release facts regarding the incident once they could be sure of their accuracy.
Richard Aylmer-Hall, 52, a media technology consultant, described "panic" on the train.
"There was panic, lots of people shouting, screaming, lots of screaming," he 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.
"I saw two women being treated by ambulance crews," he said.
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."
Natasha Wills, assistant director of operations at London Ambulance Service said in a statement 18 people were sent to hospital and none were thought to be in a life-threatening or serious condition.
The National Health Service said a total of 22 were injured - the other four had made their own way to hospital.
Earlier, Wills said: "Our initial priority is to assess the level and nature of injuries", adding that the the ambulance service had sent "multiple resources" to the station, including a hazardous area response team.
British Prime Minister Theresa May said: "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 at west London tube station."
May said she will chair a meeting of the National Security Committee later in the day.
London mayor Sadiq Khan said: "Our city utterly condemns the hideous individuals who attempt to use terror to harm us and destroy our way of life.
"As London has proved again and again, we will never be intimidated or defeated by terrorism."
He also urged all Londoners to "remain calm and vigilant" and to refer to the Transport for London website for travel advice.
Earlier, British Foreign Secretary and former London mayor Boris Johnson also appealed for calm.
Speaking to Sky News, he said: "I'm afraid my information is limited and it really is important not to speculate at the moment."
"Obviously, everybody should keep calm and go about their lives in a normal way, as normal as they possibly can," he said.