At least 38 people were injured after an explosion at the Redhill train station in Durban North yesterday.

Panicked commuters apparently jumped off a moving train at the station near Effingham Road. Four people were seriously injured.

Police spokesman Colonel Vincent Mdunge dismissed earlier reports that the train had exploded, saying an electrical box had blown up nearby.

"The loud bang caused fear and panic. Passengers from the train thought that the train had exploded and jumped off."

Barney van Eeden, a nearby resident, said: "It was about 4.30pm. I was sitting in the bakkie in my back yard when I saw the explosion. The flames shot up in the air, about 50m high ... there were white flashes.

"Then 20 seconds later there was another explosion and all the [overhead] electrical wires started sparking.

"People were jumping off the [8m high] bridge, and sliding down the grass embankment."

Last night, the busy road was cordoned off by the fire brigade and several police vehicles.

The train was on its way to Greenwood Park from Durban.

"Paramedics and emergency personnel stabilised all the injured and then transported them to various hospitals in the area for further treatment," said Botha.

Mdunge said investigators were on scene to establish the cause of the explosion.