London: An explosion on an underground train at a station in south-west London on Friday left several commuters injured and caused panic in the area, media reports said.
Several people are said to have suffered facial burns after a reported blast in a bucket towards the rear of the District Line train. Some commuters reportedly were trampled and suffered crush injuries in the rush to escape.
Transport for London (TfL) said the District Line was partially suspended because of a "security alert", the Independent reported.
A Metropolitan Police spokesman said: "Police were called at approximately 08:20hrs on Friday, September 15 to Parsons Green Underground Station following reports of an incident on a tube train.
"Officers from the Metropolitan Police Service and British Transport Police are in attendance along with the London Fire Brigade and London Ambulance Service. We would advise people to avoid the area," the spokesperson added.
While the nature of the explosion is not yet known, Met Police bomb squads and fire crews have been rushed to the station along with ambulances.
Armed police are at the scene and the Metropolitan Police urged people to avoid the area.
The city's District Line has been affected at Parsons Green station and several people are believed to have been hurt as a result of a large white plastic bucket in a supermarket plastic bag exploding in one of the carriages.
Foreign Secretary Boris Johnson appealed for calm.
"I'm afraid my information is limited and it really is important not to speculate at the moment. Obviously, everybody should keep calm and go about their lives in a normal way, as normal as they possibly can," Johnson was quoted as saying by The Telegraph.
Eyewitnesses from shops outside the station have reported seeing people with facial injuries. Many have been told to stay in lockdown until the police gives an all clear.
One witness reported seeing "a flash and a bang" in a bag holding the container, which is said to have had wires coming from it, on the packed rush-hour carriage.
A picture posted on social media appeared to show a bag that "exploded".