On Sunday, Pakistani officials confirmed that at least 140 people were killed when an oil tanker burst into flames and exploded in Bahawalpur.
It appears the tanker blew a tire while navigating a sharp bend in the road.
"According to the initial reports, somebody tried to light a cigarette," igniting spilled fuel, Reuters said, citing rescue workers service spokesman, Jam Sajjad Hussain.
Dozens of people were reportedly burnt, as they tried to collect the fuel that was leaking from the vehicle.
One source said, "People living in roadside villages, carrying domestic pots rushed to the scene to collect oil and they also made phone calls to their relatives living in other villages to immediately come to collect oil."
Military helicopters were dispatched to transport casualties to hospitals, army spokesman Maj. Gen. Asif Ghafoor said.
Police sources told Pakistani government news agency APP that the tanker had been carrying 25,000 liters (5,500 gallons) of oil when it slipped off a road and overturned in Punjab's Bahawalpur district.
The National Radio of Pakistan posted images of the horrific incident on their Twitter page.
Director of Punjab provincial rescue services, Rizwan Naseer, said the bodies were being retrieved. Many, he pointed out, had been burnt beyond recognition.
Reports have stated that some victims may only be identified through DNA sampling due to the condition of the bodies.
The blaze was reportedly extinguished by two fire engines.
The tragedy occurred one day before the beginning of Eid ul-Fitr celebrations to mark the end of the holy fasting month of Ramadan.