At least 73 people were killed and about 40 injured in Pakistan train blast on Thursday, Reuters reported.

The explosion occurred as a result of a gas canister blast that passengers used to cook breakfast, the country's railway minister said.

The fire destroyed three of the train’s carriages near the town of Rahim Yar Khan in the south of Punjab province. The train was on its way to Rawalpindi, near the capital, from the southern city of Karachi, with many people traveling to a religious gathering.

The incident was the largest railway accident in Pakistan in almost 15 years.

The problem is that people bring gas canisters to trains for cooking on long journeys, is common, said Railway Minister Sheikh Rashid Ahmed.

But several survivors questioned whether the fire was sparked by a cooking accident, as they believed the cause was a short-circuit in the train’s electrical system.