What we know so far:
- Emergency services were called at around 8.20am after reports of a bag exploding on a train
- The Met Police confirmed at 10.13am it is investigating it as a âterrorist incidentâ
- Twenty-two people received non-life threatening injuries
- Police said an âimprovised explosive deviceâ was detonated. Pictures show a flaming bucket in a bag on the train
- One witness described to HuffPost a stampede of panicked people fleeing the station
- The local hospital has declared a major incident
- The PM is chairing a Cobra meeting this afternoon
Police have confirmed the explosion on a packed rush hour tube train at Parsons Green, which injured 22 people, is being investigated as a terrorist incident.
Metropolitan Police assistant commissioner Mark Rowley said it was an âimprovised explosive deviceâ. The Metâs Counter Terrorism Command confirmed they were investigating.
Pictures on social media showed a fire in a bucket inside a Lidl bag with what appeared to be wires sticking out.
The incident caused mass panic at the station and what one witness called âa horrendous human pile-onâ as people fled.
A manhunt is now underway for the perpetrator, although reports of a man with a knife were investigated by the Met Police but later stood down.
Armed police pulled a bus over on Chelsea Bridge, but the Met Police told HuffPost UK that it was simply the case that the driver had been cold and wearing a balaclava, thus prompting concerns,
Rowley said: âThere are many urgent inquiries ongoing with hundreds of detectives involved, looking at CCTV, carrying out forensic work and speaking to witnesses.
âI am appealing for anyone who has information that would assist detectives to contact the hotline on 0800 789 321. I would also urge anyone with images or moving footage from the scene to upload them at www.ukpoliceimageappeal.co.uk.â
Deputy Assistant Commissioner Neil Basu, the senior national coordinator for counter-terrorism policing, declared it a terrorist incident nearly two hours after it happened on Friday morning.
Rowley said he understood that âmostâ of the injured were suffering from âflash burnsâ.
One man, Peter Crowley, tweeted pictures of his head after he suffered burns by the âfireballâ.
Emma Steventon, 27, who lives in Parsons Green told HuffPost UK she heard âlots of screamingâ and was told to run but didnât know why.
She said: âEveryone just got crushed on the stairs, it was like a human pile-on, stampede, it was horrendous.
âI had a lady underneath me shouting that she was pregnant and the pressure of more and more people falling on top because we couldnât get down the stairs quickly enough.â
Witness Olaniyi Shokunbia told HuffPost the explosion and stampede happened within 15 seconds.
He said: âItâs just crazy. Iâm thinking Iâm lucky that train was stationed what if this has happened if the train was leaving. I was in the middle of the train I think it happened at end of train.
âI saw masses of people running so I started running myself. Iâm saying to you weâre running down stairways I see people jumping into people.
St Maryâs Hospital in Paddington declared a major incident.
Firefighters were called at 8.21am and the London Ambulance Service sent a hazardous area response team. It arrived on the scene within five minutes and treated 19 people âmostly for minor injuriesâ.
People shared images and video of what appeared to be the bag that exploded on the train.
It shows a flaming bucket within a Lidl bag on the carriage floor.
The BBC is reporting that the device was on a timer.
Theresa May, who is charing a Cobra meeting about the incident this afternoon, tweeted: âMy thoughts are with those injured at Parsons Green and emergency services who are responding bravely to this terrorist incident.â
London Mayor Sadiq Khan called the perpetrators âevilâ and cowardlyâ.
He said: âOur city utterly condemns the hideous individuals who attempt to use terror to harm us and destroy our way of life.
âAs London has proven again and again, we will never be intimidated or defeated by terrorism...
âI urge all Londoners to remain calm and vigilant, and to check Transport for Londonâs website for travel advice.â
Home Secretary Amber Rudd said: âOnce more people going about their everyday lives have been targeted in a callous and indiscriminate way.â
Transport for London warned people travelling between Wimbledon and Earlâs Court on the District Line to find an alternative route.
Police later stopped a London bus near Chelsea Bridge but a Metropolitan Police spokesman said this was because the driver was wearing a balaclava but it turned out he was just cold.
Jeremy Corbyn tweeted his thoughts were with victims and those responding.
The incident follows previous terror attacks in London and Manchester this year, which saw terror-related arrests have surged to a new record high.
New figures revealed earlier this week that there were 379 arrests for terrorism-related offences in Great Britain in the year ending June 2017 - a rate of more than one a day and the highest number in a year since data collection began in 2001.