Police said the tanker’s fuel tank was being repaired at a garage on Haaji Bunder Road, Sewri, when the incident occurred. The tanker was brought to the garage after the fuel tank developed a leak, an officer said.

“Riyaz Sheikh (50) was welding the fuel tank’s lid when some sparks entered the fuel tank. Prima facie, it is believed that the sparks came into contact with some residual diesel inside the fuel tank, leading to an explosion. It is also possible that the presence of fumes in the fuel tank might have caused the blast. Sheikh and the tanker’s cleaner Lal Bahadur (22) suffered severe burns,” said an officer with the Sewree police.

Both were taken to a nearby private hospital where Bahadur succumbed to burn injuries. Sheikh is out of danger, the police said.