The vehicle was proceeding from Guwahati in Assam after refuelling, towards Silchar in Barak valley. It exploded in Garikhana, on the national highway 44 near the office of Khasi Hills Autonomous District Council.
No one was injured. Firefighters arrived to put out the flames. The vehicle has been towed away, police said.
H.G Lyngdoh, additional superintendent of police, Shillong, said: 'Investigations is on to find out the cause of explosion. The vehicle has been removed.'