NEW DELHI (AP) — A suspected short circuit sparked a fire on a passenger bus in northern India on Tuesday, rapidly engulfing the vehicle in flames and burning at least 20 people to death, authorities said.

The bus with 35 to 50 passengers aboard was minutes from starting its journey between the towns of Jaisalmer and Jodhpur in Rajasthan state when the fire broke out, local ruling party lawmaker Mahant Pratap Puri told The Associated Press.

“Passengers didn’t get time to deboard the bus as the fire spread quickly," Puri said.

The bodies of 19 passengers were recovered from the bus, while one person succumbed to their burns on the way to a hospital, Puri said. At least 15 passengers were critically injured and admitted to a hospital for treatment.

Smoke began to emerge from the vehicle’s rear due to a suspected short circuit barely five minutes after it departed Jaisalmer, Puri said. The driver managed to stop the bus along the roadside near a military station, but within moments, the flames engulfed the vehicle.

“It was a new bus with full load of air-conditioning gas. There was just one door for entry and exit. Unfortunately, the passengers seated on the rear end couldn’t make it to the exit and were burnt alive,” said Puri, who was at the scene as local government and military officials launched rescue efforts.

The local government issued an appeal for information from relatives to confirm the identity of victims, and planned to identify remains using DNA evidence.

Prime Minister Narendra Modi and Rajasthan’s highest elected official, Bhajan Lal Sharma, offered their condolences to the bereaved families.