An oil tanker crashed on a road near Bahawalpur on Sunday and more that 153 people, many of whom had rushed to collect leaking fuel, were killed when it exploded.
The tanker carrying 40,000 litres of fuel overturned after trying to make a sharp turn while travelling from Karachi to Lahore on the main highway.
Nearly a hundred people were injured as a result of the incident, the government officials said.
A doctor at Bahawalpur's Victoria Hospital in south Punjab said the latest deaths occurred at a hospital in Multan where some of the 50 critically injured were taken, many of them suffering extensive burns.
A senior rescue official in the area said the death toll could rise further as dozens are still in critical condition.
The disaster occurred when hundreds of residents of a nearby village gathered at the site of an overturned oil tanker to collect the leaking fuel. It's believed that a spark from the many cars and motorcycles that raced to the scene ignited the fuel.
Dr. Mohammad Baqar, a senior rescue official in the area, confirmed the latest toll, updating a previous figure.
He says many of the bodies were burned beyond recognition and will have to be identified through DNA testing.
“When [the tanker] turned over the residents of the nearby village of Ramzanpur Joya rushed to the site with buckets and other containers, and a large number of people on motorcycles also came and started collecting the spilling fuel,” regional police chief Raja Riffat said.
“After about 10 minutes the tanker exploded in a huge fireball and enveloped the people collecting petrol. It was not clear how the fire started.”
Motorway Police spokesman Imran Shah said police raced to the scene and tried to keep people away from the tanker but they were ignored as residents continued filling their containers with fuel.
At least six cars and 12 motorcycles were burnt in the blaze.
The charred wreckage of the motorcycles and cars could be seen scattered on the highway, along with kitchen utensils, pots, water coolers, jerrycans and buckets which victims had brought to collect the petrol.
The fire brigade arrived on the site of the incident shortly after the blaze started and rescue operations were initiated.
Firefighters fought the flames for over two hours before extinguishing the fire.
The injured were transferred to District Headquarters Hospital and Bahawal Victoria Hospital, rescue officials said. They added that all bodies were removed from the site of the incident and only the damaged vehicles remained.
Dr. Rizwan Naseer, director of Punjab provincial rescue services, said many of the badly burnt bodies are beyond recognition.
At least 40 amongst the injured are in critical conditions and are being transferred to hospitals in Multan for treatment.
Ten injured of the Bahawalpur oil tanker incident will be airlifted to Faisalabad airport through a C-130 aircraft, from where they will be shifted to the burns centre in Allied hospital Faisalabad, says Deputy Commissioner Salman Ghani.
He said all arrangements has been finalised for treatment of the injured.
Chief of Army Staff (COAS) Gen Qamar Javed Bajwa ordered the army to assist the civil administration in the rescue efforts.
Army helicopters were used to transport 51 injured people from Bahawalpur to Nishtar Hospital in Multan.
"COAS expresses grief on losses in oil tanker incident. Directed provision of full assistance to civil administration in rescue [and] relief efforts," Director General of the Inter-Services Public Relations (ISPR) Major Gen Asif Ghafoor said in a tweet.
"Army Aviation helicopters sent for evacuation of casualties to hospitals [and] burn centres. Hospitals placed on high alert," he added.
The prime minister's office said the Punjab provincial government had been directed to provide full medical assistance.
“Prime Minister Nawaz Sharif has expressed deep grief over the heavy loss of life in the unfortunate accident of oil tanker fire at Ahmad Pur Sharqia, Bahawalpur,” the statement said.
Punjab Chief Minister Shahbaz Sharif took notice of the incident and ordered government officials to file a report.
Citizens expressed their grief on social media, sharing messages of sorrow with two deadly bombing attacks in Quetta and Parachinar in the backdrop.