Pakistan's prime minister cut short a trip abroad Sunday to visit victims of a massive fuel tanker fire and explosion near Bahawalpur that authorities now say is responsible for the deaths of 157 people.

Nawaz Sharif, who visited the Victoria Hospital in Bahawalpur on Sunday after returning from London, England, ordered that more of the most critically hurt be transferred to bigger hospitals in the area, rescue official Mohammad Baqar said.

Sharif also announced two million rupees (nearly $40,000 Cdn) as financial assistance for each family who had lost a relative in the highway inferno, and handed over cheques of one million rupees ($20,000 Cdn) for each burn victim being treated.

"This is not compensation — no compensation is possible for precious human life — but it is to help the affected families in distress," Sharif said.

The truck, carrying some 25,000 litres of gasoline, was travelling from the southern port city of Karachi to Lahore, the Punjab provincial capital, when the driver lost control and crashed on a highway outside the town of Bahawalpur early on Sunday.

After being alerted by an announcement over a mosque loudspeaker that an overturned tanker truck was leaking fuel, scores of villagers rushed to the scene to collect the spilled fuel when the blaze ignited. The wreck exploded, engulfing people in flames.

Dr. Nahid Ahmed, who was at the Nishter Hospital in Multan, about 100 kilometres away from the site of the fire, said four of the victims brought from Bahawalpur had died overnight, bringing the death toll to 157. Ahmed said 50 more severely burned victims were being treated at his hospital.

Pakistan Deadly Fire

Pakistani officials on Monday increased the death toll to 157. Dozens more were being treated in hospital. (Iram Asim/Associated Press)

Baqar said a military C-130 plane transported 20 victims from the Bahawalpur hospital on Monday to Lahore for better medical care.

Many of the bodies were burned beyond recognition and will have to be identified through DNA testing, said Baqar.

"I have never seen anything like it in my life. Victims trapped in the fireball. They were screaming for help," said Abdul Malik, a police officer who was among the first to arrive on the scene of horror in Pakistan's Punjab province.

When the flames subsided, he said, "we saw bodies everywhere. So many were just skeletons. The people who were alive were in really bad shape."

With files from Reuters