Six trucks exploded into flames after a fiery crash that shut down a major NSW highway early on Tuesday morning, with all drivers miraculously surviving.

Two trucks appear to have initially collided and careered into several other rigs at a roadside stop on the Hume Highway near Gunning, on the Southern Tablelands.

Six trucks were destroyed in the incident which happened around 5am. 

All of the six truck drivers managed to escape relatively unharmed, despite their vehicles being entirely consumed by the flames.

The trucks were transporting loads that fuelled the intensity of the fire. Photo: Nine News

Rescue crews initially believed one of the drivers was unaccounted for, but several hours later realised the incident only involved six trucks and that all of the drivers had escaped with only a few suffering minor injuries.

NSW Police say initial inquiries suggest two of the trucks collided as they attempted to enter a roadside rest stop just after 5am near Gunning in the state’s Southern Tablelands.

One of the trucks appears to have collided with the rear of the other vehicle and shunted it into the others that were parked at the rest stop, police said.

One of the trucks was carrying eight tonnes of butane cans, resulting in multiple small explosions when fire crews arrived at the scene.

Also fuelling the resulting fire were loads of alcohol, resin, and memory foam being transported in the other trucks.

Several trucks were destroyed after a fiery collision near Gunning in the NSW Southern Tablelands. Photo: NSW Fire and Rescue 

“Emergency services were confronted with a fairly horrific scene this morning,” Hume Police District Inspector Vlad Mijok said on Tuesday.

All six trucks were destroyed but the male drivers were treated only for minor injuries, according to NSW Police.

Mijok described the escape as “nothing short of a miracle”.

Two of those drivers were taken to Goulburn Hospital for mandatory testing, police said.

Fire and Rescue NSW deployed seven fire trucks, including two Hazardous Materials vehicles and up to 40 firefighters, to the scene.

NSW Ambulance responded to the crash and treated six male drivers for minor injuries. Police said two were taken to Goulburn Hospital for mandatory testing.

The Hume Highway remained closed in both directions as of 11am AEST.

Police said it may take some time to reopen the road given the extent of debris and potentially hazardous materials left in the wake of the crash.

A crime scene had been established and the Crash Investigation Unit will assist with investigations.

-with AAP