At least 18 people were injured, many with burns, following a blast early Friday on a packed rush-hour commuter train in London. Police are treating the event as a terrorism incident.
London Subway Explosion

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An injured woman is led away after an incident at Parsons Green underground station in London, Britain, September 15, 2017.

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Deputy Chief Constable Adrian Hanstock of the British Transport Police makes a statement to the media after an incident at Parsons Green underground station in London, Britain, Sept. 15, 2017.

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A police forensic officer stands beside the train, at left, where an incident happened, that police say they are investigating as a terrorist attack, at Parsons Green subway station in London, Friday, Sept. 15, 2017.

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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.