NHS England has said 19 people were taken to hospital by ambulance and three went to hospital by themselves.

Earlier, the London Ambulance Service said it had taken 18 patients to hospital.

Luke O'Connor from Lichfield, Staffordshire, was travelling on the District Line when he heard a "loud explosion" at Parsons Green.

The BBC's security correspondent Frank Gardner explains about the manhunt which will be happening to find the person who left the device on the Tube train.

Rachel Green, 18, helped people as they left the station.

Image source, AFP

London Fire Brigade say there are currently six fire engines, two fire rescue units and around 50 firefighters and specialist officers at Parsons Green.

Director of operations Tom George said crews were at the scene within three minutes and assisted ambulance crews in treating casualties while also helping to evacuated 253 people from another Tube train.

The brigade say fire crews from Fulham, Wandsworth, Chelsea, Hammersmith and other surrounding fire stations are in attendance.

The BBC's Leila Nathoo explains more about the Cobra meeting which was held following the explosion at Parsons Green.

Emma was at Parsons Green when an explosion on a train triggered a crush of people fleeing.

Donald Trump has threatened to spark a new row over intelligence-sharing between Britain and the US after he claimed the Parsons Green Tube bombers had been "in the sights" of Scotland Yard.

In a tweet, the US president called for a "proactive" response to dealing with the terrorist threat and the "sick and demented people" responsible "were in the sights of Scotland Yard."

His comments, which did not correspond with information released by the Metropolitan Police, were condemned as "unhelpful" by former No 10 aide Nick Timothy.

"True or not - and I'm sure he doesn't know - this is so unhelpful from leader of our ally and intelligence partner," he tweeted.

Scotland Yard refused to be drawn on the remarks.

It comes after British police temporarily suspended intelligence-sharing with the US in the wake of the Manchester Arena bombing in May following a series of leaks to American media.

BBC reporter Louise Martin says part of King's Cross station in London was briefly cordoned off after a "suspicious item" was found.

Passengers were moved to the main concourse but the area has now been reopened.

Ryan Barnett, 25, tells Press Association he was caught in the "stampede" of people trying to get out of Parsons Green station.

"I was sitting there, headphones in, at Parsons Green, the doors open fine, I'm not really paying attention and all of a sudden hundreds of people run past me screaming a mixture of 'stampede', 'attack', 'terrorist', 'explosion', 'get off the train', 'everyone run'," he says.

"Parsons Green station has a staircase at the front of the carriage where the train pulls up - I'm running and keeping my head down because there might be gunfire and on to the staircase.

"It is absolute chaos, it was quite scary because at one stage we thought we might be trapped there - I heard a pregnant woman lost her shoes and had fallen over.

"It felt like an eternity, but it was only a couple of minutes, probably."

Londoners have taken to social media offering to "put the kettle on" for people affected by the explosion in Parsons Green.

Katy Dunn posted on Twitter: "If anyone is feeling shocked or confused at #ParsonsGreen, I'm round the corner and the kettle's on."

James Edge tweeted: "Anyone who's now stuck in Parsons Green/Fulham drop me a line and I'll get the kettle on! #ParsonsGreen."

Angela Merkel has said the terror incident at Parsons Green has strengthened her resolve to fight terrorism.

Speaking after talks with the French prime minister Eduoard Philippe, the German chancellor said her thoughts were with those injured and that Germany was united with the British government and the British people.

New York's governor has tweeted about the explosion:

Supermarket Lidl has offered to assist a police investigation into the terrorist incident on the London Underground, after one of its bags was apparently used to hold the improvised bomb.

Image source, Sylvain Pennec

The German-owned grocery chain issued a statement soon after social media photos of the affected District Line carriage showed a still-burning bucket inside a Lidl-branded reusable bag.

"We are shocked and concerned to have learned of an incident at Parsons Green this morning and our thoughts are with those affected," Lidl UK said.

"We will, of course, support the authorities should they need our assistance in their investigations. We are closely monitoring the situation as it develops over the course of the day."

BBC London Travel
BBC Radio London Travel

Image source, Getty Images

There continues to be no service on the District Line between Earl's Court and Wimbledon while police continue their investigation at Parsons Green. There are severe delays between Earl's Court and Edgware Road. There are minor delays between Ealing Broadway to Turnham Green.

Around Parsons Green the A304 Fulham Road between Munster Road and A3219 North End Roa is closed as is Parsons Green Lane and New Kings Road.

There are delays around Putney, Fulham, Wandsworth and Chelsea. Four bus routes are on diversion.

Broadcast engineer David Nelson, who was in the Tube carriage when the explosion happened, describes what happened.

The home secretary has released a statement about the explosion:

Police are appealing for people to give them any photos or video they may have from the Parsons Green incident. They have set up a web page to make it easy for such images to be submitted., external