The explosion left most of the bodies charred beyond recognition, and the death toll could rise because dozens of victims are still in critical condition, The Associated Press reported, citing Dr. Mohammad Baqar, a senior rescue official in the area.
At least 73 motorbikes and several cars were also destroyed in the blast, which occurred the day before Pakistan celebrates Eid al-Fitr, the Muslim holiday at the end of Ramadan.
The injured were taken to the district hospital and Victoria Hospital in neighboring Bahawalpur, but the response was hindered by a shortage of facilities to treat burn victims. Arrangements were being made to take the seriously injured to a hospital in Multan, about 80 miles to the north, which has a burn-treatment unit. The Pakistan Army said it had sent two helicopters to help with the rescue efforts.
Poverty is endemic in parts of Pakistan — the World Bank calls the country one of the lowest performers in South Asia — and oil is a valuable resource for its people, who use it for heating and cooking.
Abdul Rashid, 30, one of those injured, said he and his friend had joined in collecting the spilled fuel after passing by the area and seeing people trying to scoop it up from the overturned tanker.
“I parked my bike by the road and waited while my friend went to collect the fuel,” said Mr. Rashid, who had burns on his hand and a leg. “We did not have any bottles, so we asked people and got one. The bottle was small, so my friend went thrice to collect the fuel.”
He said he did know what had happened to his friend after the fire broke out.
There were no immediate information about why the tanker had overturned: speeding at a sharp turn, a burst tire or something else. .