One of the busiest tube stations on London has been evacuated, with two people taken to hospital, after smoke filled a train carriage and platform.
Pictures on social media show grey smoke billowing out of the carriage on the Bakerloo line while passengers stand on the platform covering their mouths and noses.
Other photographs show people standing in dark, smoke-filled carriages covering their faces with items of clothing.
Oxford Circus station, which services London's busiest shopping street and sees thousands of commuters pass through it during the rush hour, was closed after the incident.
A London Ambulance Service spokesman said a team was at the station in less than five minutes.
"We treated four patients at the scene for smoke inhalation and have taken two to hospital as a precaution," he said.
A London Fire Brigade spokesman said firefighters "dealt with a small fire on a train on the Bakerloo line at Oxford Circus" and that the cause of the blaze is being investigated.
A video taken by a passenger appears to show the Tube train in a tunnel and an alarm can be heard beeping.
Joe Bunting tweeted: "Fire on the bakerloo line Oxford circus today - great Friday start."
While @lucyjanefunnell posted: "There's a fire at #OxfordCircus tube. Bakerloo line is on fire and you can smell the black smoke going through. Hope everyone is ok!"