In what police are treating as a terrorist attack, an explosion and fire on a train left multiple people injured. The incident happened during morning rush hour in London on Friday.
See photos from the scene in the gallery above.
This is an image made from video showing burning items in underground train at the scene of an explosion in London Friday, Sept. 15, 2017. (Sylvain Pennec via AP)
An armed police officer stands nearby after an incident on a tube train at Parsons Green subway station in London, Friday, Sept. 15, 2017. (Frank Augstein/AP Photo)
Police officers walk with a dog within a cordon near where an incident happened, that police say they are investigating as a terrorist attack, at Parsons Green subway station. (Kirsty Wigglesworth/AP Photo)
Police forensic officers walk within a cordon near where an incident happened, that police say they are investigating as a terrorist attack, at Parsons Green subway station. (Kirsty Wigglesworth/AP Photo)
A police forensic officer stands beside the train, at left, where an incident happened, that police say they are investigating as a terror attack, at Parsons Green subway station. (Frank Augstein/AP Photo)
Metropolitan Police Assistant Commissioner Mark Rowley speaks to the media outside New Scotland Yard, gives a statement about a terrorist attack at Parsons Green subway station. (Victoria Jones/PA via AP)
''I'm safe - just had to run for my life at #ParsonsGreen station,'' wrote Emma Stevie on Twitter. (EmmaStevie1/Twitter)
An injured woman is assisted by a police officer close to Parsons Green station in west London after an explosion on a packed London Underground train, Friday, Sept. 15, 2017. (Stefan Rousseau/AP Photo)
An injured woman is assisted by a police officer close to Parsons Green station in west London after an explosion on a packed London Underground train, Friday, Sept. 15, 2017. (Dominic Lipinski/PA via AP)
Police officers stand at the scene of a southwest London subway station after an explosion in London Friday, Sept. 15, 2017. (RRIGS via AP)
People leave the scene of an explosion at a southwest London subway station in London Friday, Sept. 15, 2017. (Alex Littlefield via AP)
Armed police close to Parsons Green station in west London after an explosion on a packed London Underground train, Friday, Sept. 15, 2017. (Dominic Lipinski/PA via AP)
Police stand by a cordon near Parsons Green subway station in London, Friday, Sept. 15, 2017. (Frank Augstein/AP Photo)
In this image made from video, fire raises at a southwest London subway station in London Friday, Sept. 15, 2017. (RRIGS via AP)
Police enter a building near Parsons Green subway station in London, Friday, Sept. 15, 2017. (Kirsty Wigglesworth/AP Photo)
A police officer holds cordon tape near Parsons Green subway station in London, Friday, Sept. 15, 2017. (Frank Augstein/AP Photo)
An ambulance leaves a cordon after an incident on a tube train at Parsons Green subway station in London, Friday, Sept. 15, 2017. (Frank Augstein/AP Photo)