Sao Paulo 36-vehicle pile-up is caused by colliding trucks

Two people have been killed and at least a dozen injured when a 36-vehicle pile-up turned into a burning inferno in the Brazilian city of Sao Paulo on Wednesday.

The crash took place during morning rush hour, around 7.45am, on a motorway overpass running through the Sao Paulo suburb of Jacarei.

Two trucks collided on the busy bridge, after which dozens of cars slammed into each other in quick succession.

Car crash:  Two trucks collided during early morning rush hour, and more than 30 other vehicles soon crashed into them

Tragedy: A can can be seen overturned on top of another car, next to what is left of a handful of vehicles which had been engulfed in flames

One truck had been ferrying ink, and the other scrap metal, and as cars continued to extend the pile-up, flammable material aboard one of them detonated.

The fire engulfed several vehicles and spread down the line of cars as motorists fled for their lives. 

Heavy smoke caused visibility problems as emergency services arrived to put out the fire and attend to the injured.  

Accident: Soon after the two trucks collided on the motorway overpass, dozens of cars crashed into each other one by one

Emergency: What is left of the trucks and their contents is inspected by at the scene

Burned out: It is believed that flammable material from one or both of the trucks is what started the fire in the wake of the crash

Video of the aftermath of the incident shows vehicles reduced to charred metal. 

Authorities said one victim was believed to have been struck after he exited his vehicle to avoid the fire. 

Another victim died when his car got stuck between the trucks.