London Underground terror attack Live updates: Possible suspect identified, manhunt underway

"Security sources say they've identified a suspect involved in the Parsons Green bombing, with the aid of CCTV footage," Mark White, a home affairs correspondent for Sky News, said on Twitter. 

British security services have identified a suspect involved in the bombing of a busy commuter train in west London with the help of surveillance footage, Sky News reports.

British PM Theresa May says London train bomb intended to cause 'significant harm'

Mayor Sadiq Khan urges London citizens to remain calm and vigilant

"As London has proven again and again, we will never be intimidated or defeated by terrorism," he said in a statement.

Mayor of London tweets: "London will never be intimidated or defeated by terrorism"

Labour Party leader Jeremy Corbyn expresses condolence on Parsons Green terror attack, tweets: 

"Thoughts with those injured in Parsons Green terrorist incident, and thanks to police, ambulance staff and firefighters who are responding."

A former Ministry of Defence Head of Counter-Terrorism told Sky News that the IED device used in the explosion at the train was attached to a timer. The device malfunctioned and did not fully detonate.

The device found at Parsons Green station was attached to a timer, reported Sky News Newsdesk. 

The Government's emergency Cobra committee will discuss the UK's terror threat level, it further said. 

Former British PM David Cameron reacts to London terror attack, tweets: 

"My thoughts with all those affected by the appalling terrorist incident at Parsons Green. Thank you to emergency services for swift response."

London Police warns people of heightened police activity over weekend:

AC Rowley: “Today & over the weekend you can expect to see a heightened police presence, particularly in crowded places” #ParsonsGreen

— Metropolitan Police (@metpoliceuk) September 15, 2017

AC Rowley “Urgent inquiries ongoing with detectives looking at CCTV, carrying out forensic work & speaking to witnesses” #ParsonsGreen pic.twitter.com/KYIXTjRGIJ

— Metropolitan Police (@metpoliceuk) September 15, 2017

London Police examines CCTV footage; urges people to report any info

London Police urges people to dial hotline numbers 0800 789 321, 999 for info or in case of emergency

US President Donald Trump condemns London terror attack. He called for tough action to deal with the "loser" terrorists.

"Another attack in London by a loser terrorist.These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!" Trump tweets.

"Loser terrorists must be dealt with in a much tougher manner.The internet is their main recruitment tool which we must cut off & use better!"

`Improvised Explosive Device` used in London train attack, confirms police.

Home Secretary Amber Rudd says her "thoughts are with the victims of the terrorist attack".

London Ambulance confirms that 18 patients have been taken to hospitals. None are thought to be in a serious or life-threatening condition.

The device used during an incident at a London metro station did not fully detonate, Sky News reported, citing unnamed sources.

British Prime Minister Theresa May says her "thoughts are with those injured" in a terrorist incident.

"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," May says.

She will chair an emergency cabinet meeting later today.

London Mayor says the Metropolitan Police have confirmed that the explosion on a train at Parsons Green Station this morning is being treated as terrorism.

The Mayor of London took to Facebook to express solidarity with the Londoners.

Here's his post:

Our city utterly condemns the hideous individuals who attempt to use terror to harm us and destroy our way of life.

As London has proven again and again, we will never be intimidated or defeated by terrorism.

I am in close contact with the Metropolitan Police Service, Transport for London, Government and other emergency services who are responding at the scene and leading the investigation. I will be attending the emergency COBRA meeting in Whitehall this afternoon with the Prime Minister.

My sincere gratitude goes to all our courageous emergency responders and the TfL staff who were first on the scene.

I urge all Londoners to remain calm and vigilant, and to check Transport for London's website for travel advice

London Underground service update: No service between Earls Court - Wimbledon and Ealing Broadway - Turnham Green eastbound service.

UK Police asks people to send them images of Parsons Green incident.

"Help us investigate. Anyone with images of #ParsonsGreen incident asked to upload images to: http://ukpoliceimageappeal.co.uk," British Transport Police tweets.

"Deputy Assistant Commissioner Neil Basu, the senior national coordinator for CT policing, has declared it a terrorist incident," the Metropolitan Police said in a statement on Friday. 

The Met’s Counter Terrorism Command are investigating after the incident at Parsons Green tube station is declared a terrorist incident.

Police have now declared this a terror incident. Officers remain at the scene and continue to work with emergency service colleagues.

Daniel Sandford, Home Affairs Correspondent at BBC claims that Counter terrorism sources say their working assumption is that the Parsons Green incident is "terrorism".

Witnesses reported seeing passengers who had suffered facial burns and had hair coming off.

"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.

Explosion on Parsons Green district line train. Fireball flew down carriage and we just jumped out open door. pic.twitter.com/pGbfotbfsJ

— Rigs (@RRigs) September 15, 2017

London Fire Brigade releases emergency number

"Seen something suspicious? Just ACT. Call 0800 789 321 In an emergency always call 999 #ActionCountersTerrorism," London Fire Brigade tweets.

Police asks Londoners to remain vigilant and report to them about any suspicious behaviour.

"We ask everyone to remain vigilant and to report any suspicious behaviour to us by texting 61016 or calling 0800 405040," BTP tweets.

Police repeatedly urge Londoners to avoid the area.

"Officers attended with @BTP along with @LondonFire & @Ldn_Ambulance We would advise people to avoid the area. More info as we get it," Metropolitan Pollice tweets.

London Fire Brigade says the have number of resources and specialists officers deployed at the incident site.

Six fire engines, two fire rescue unit and around 50 firefighters and specialist officers are currently attending an incident at Parsons Green Tube station.

The Brigade was called at 0821. Fire crews from Fulham, Wandsworth, Chelsea, Hammersmith and other surrounding fire stations are in attendance.

A Metropolitan Police Service spokesperson said: "Police were called at approximately 08:20hrs on Friday, 15 September 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.

"We would advise people to avoid the area."

London Ambulance Service assures that they have a number of resources on scene at Parsons Green underground station.

Statement of London Ambulance Service on the incident at Parsons Green - 

Natasha Wills, Assistant Director of Operations at London Ambulance Service said:

“We were called at 8:20 am to reports of an incident at Parsons Green underground station.

“We have sent multiple resources to the scene including single responders in cars, ambulance crews, incident response officers and our hazardous area response team, with the first of our medics arriving in under five minutes.

“Our initial priority is to assess the level and nature of injuries. More information will follow when we have it.” 

BBC correspondent Riz Lateef, who was at the station travelling to work, says 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."

Transport for London confirms the explosion incident at Parsons Green Station.

"We're aware of an incident at #ParsonsGreen station. Officers are at the scene. The station is closed. More information as we get it," British Tranport Police tweets.

Heavily armed police area at the spot and have cordoned off the area.