A blast on a London underground train left some passengers with facial burns, London’s Metro newspaper reported on its website.
Police said they were aware of an incident at Parsons Green station in West London and that officers are in attendance. London Ambulance said paramedics were present.
A Transport for London spokeswoman said the District line has been suspended between Earls Court and Wimbledon due to a security alert.
Images posted on Twitter showed a women being attended to by emergency services sitting on a pavement.
Transport for London said on Twitter that there was no service between Earls Court and Wimbledon on the District Line which runs through Parsons Green.
The Metropolitan and British Transport police forces, as well as the London ambulance service, were all on the scene, though none was immediately able to provide further details on what had happened.
The Metropolitan Police said they were aware of the incident but could not provide further information