A massive fireball erupted from the Elephant and Castle train station in south London on Monday afternoon, sending commuters running to safety, social media videos show.

Almost 100 firefighters and 10 fire engines were tackling the large blaze as smoke engulfed the station and swelled up into the air. The city’s fire brigade received “nearly 50” emergency calls from people near the station, a station commander said.

A London Fire Brigade official said there was “a significant fire in a car garage in the railway arches,” affecting several nearby cars and a telephone box.

Six people are being treated in an ambulance near the station and police are evacuating nearby residents and merchants. People are being asked to avoid the area.

The National Rail, the country’s rail network operator, said the trains are no longer running through the station and services are likely to be disrupted until Monday evening.

Officials said that “dangerous chemicals” may be a factor in the fire. However, the cause of the fire is still unknown.