Two road trains collide on Berrimah Road at East Arm near Darwin

The driver of a road train involved in a horror crash has been upgraded to a critical condition, according to Northern Territory Police.

Two road trains crashed on Berrimah Road at East Arm, near Darwin, causing one of the vehicles to be engulfed in flames.

One road train has been completely destroyed and NT Police were asking people to avoid the area.

NT Fire and Rescue Service watch commander Scott Perry said the crash took place about 11:00am a little more than a kilometre from Darwin's main fire station, so emergency crews arrived swiftly to the scene.

‘When we first arrived one vehicle [was] fully involved and a gentlemen was under the trees being taken care of by two rescue members’ he said.

The driver of one truck was taken to Royal Darwin Hospital with serious burns to large parts of his body.

The injured man was driving a truck carrying gravel, which is believed to have hit the other truck and then burst into flames.