Heavily armed police rushed to the venue of an incident at a London underground station on Friday with local media reporting that there had been an explosion on a train.
Reuters witness said that he saw six ambulances, fire engines and a helicopter at Parsons Green station in West London.
Passengers had suffered facial burns from a blast and others had been hurt in a subsequent stampede at the station.
Outside the station, a woman was sitting on a pavement with a bandage around her leg while armed police patrolled.
A Reuters witness saw a woman being carried off on a stretcher with her legs covered in a foil blanket.
“We are aware of an incident at #ParsonsGreen tube station.
Officers are in attendance,” London police said.
Police said they were aware of reports on social media and would release facts regarding the incident once they could be sure of their accuracy.
London Ambulance and Fire Brigade said paramedics and firefighters were present.
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.
Britain has already suffered four attacks blamed on terrorists so far this year which killed 36 people.
However, the British police have advised people to avoid the area near Parsons Green, a west London underground station, after the reports of the blast on a train.
“Officers from the Metropolitan Police Service and British Transport Police are in attendance along with the London Fire Brigade and London Ambulance Service,” the London’s police said in a statement.
“We would advise people to avoid the area.”