London (CNN)Dozens of firefighters are tackling a large blaze at the Elephant and Castle train station in south London, the city's fire brigade has said.
Video posted to social media showed smoke billowing from the station on Monday afternoon.
The London Fire Brigade said 10 fire engines and approximately 70 firefighters were attending the scene, and urged people to avoid the area. Six people were treated at the scene and one of them was taken to hospital, the London Ambulance Service said.
National Rail, the UK's rail network operator, said in a statement that the fire occurred "next to the track," while Southwark Police tweeted that the incident is "not believed to be terror related."
One video posted to social media appeared to show a fireball pouring out from underneath a railway arch and onto Elephant Road, near a pedestrian entrance to the overground train station.
The service added it had received "nearly fifty" emergency calls from people near the station. The cause of the fire is not known.
Trains are no longer running through the station and services are likely to be disrupted until Monday evening, National Rail said.
The site also houses a major underground station, which links two subway lines on London's Tube network.