Police and the London Ambulance Service are attending the scene of a reported explosion on a London Underground tube at Parsons Green station. The Metropolitan Police has confirmed it is being treated as a terrorist incident.
The London Ambulance service said that 22 people have been taken to a number of London hospitals, but 'none are thought to be in a serious or life-threatening condition'.
Met Police Assistant Commissioner Mark Rowley said the explosion was caused by the detonation of an improvised explosive device.
Rowley added it was understood that 'most' of the 22 injured were suffering from 'flash burns'.
Assistant director of Operations at London Ambulance Service Natasha Wills said earlier on Friday: 'We were called at 8.20am to reports of an incident at London 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.
'Our initial priority is to assess the level and nature of the injuries. More information to follow when we have it.'
An image shared on social media showed a white bucket on fire in a plastic shopping bag, which didn't appear to show damage to the tube carriage.
Metropolitan Police asked 'everyone to remain vigilant' and advised people to avoid the area.
London Fire Brigade were also on the scene, tweeting: 'We have a number of resources and specialists officers in attendance at the incident at #ParsonsGreen tube station.'
TFL said that services between Edgware Road and Wimbledon had been suspended while police responded to the incident.
A commuter whose train had just left the Parsons Green station in southwest London said there was panic after a woman on the platform saw what appeared to be an explosion. Richard Aylmer-Hall also said he saw several people injured, apparently trampled as they fled.
'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 commented.
'Some people got pushed over and trampled on, I saw two women being treated by ambulance crews.'
He added he did not believe anyone was hurt by the actual device.
Prime Minister Theresa May said her 'thoughts are with those injured at Parsons Green and emergency services who are responding bravely to this terrorist incident.'
The Met Police SO15 Counter Terrorism Command is leading the response.
The police are urging anyone who has any information to contact the hotline 0800 789 321.
This story is being updated. Additional reporting from Associated Press.
Naomi Gordon is news writer mainly covering entertainment news with a focus on celebrity interviews and television.
