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, citing security sources.
"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.
A home-made bomb exploded on a packed rush-hour commuter train injuring 22 people on Friday, in what was being treated as the fifth terrorism attack in Britain this year.
Passengers on board a train heading into the capital fled as fire engulfed a carriage at Parsons Green underground station in West London after the explosion at 8.20am.
Some suffered burns while others were injured in a stampede to escape. The National Health Service said 22 people had been taken to London hospitals. None were thought to be in a serious condition, the ambulance service said.
Pictures taken at the scene showed a white bucket with a supermarket freezer bag on the floor of one train carriage. The bucket was in flames and there appeared to be wires coming out of the top.
"I was on second carriage from the back. I just heard a kind of whoosh. I looked up and saw the whole carriage engulfed in flames making its way towards me," Ola Fayankinnu, who was on the train, said.
"There were phones, hats, bags all over the place and when I looked back I saw a bag with flames."
Prime Minister Theresa May returned to London to chair a meeting of Britain's emergency response committee later on Friday. She said the official terror threat would remain at severe rather than being raised to critical, which indicates an imminent attack.
"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 said.
"This was a device intended to cause significant harm."
She wasn't the only world leader to condemn the attack.
"Another attack in London by a loser terrorist," US President Donald Trump said on Twitter.
"These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!"
The comments drew a quick rebuke from May, who was asked on television about Trump's tweets.
"I never think it's helpful for someone to speculate on what is an ongoing investigation," she responded.
Scotland Yard said the area surrounding Parsons Green Tube station has been evacuated so specialist officers could "secure the remnants of the improvised device and ensure it is stable".
"A small number of residents will be affected by the evacuation, which encompasses an area approximately 50 metres in radius," a spokesman added.
The Tube station remains closed.