The scene where an overturned tanker burst into flames in Pakistan on Sunday. Many people had rushed to the scene to collect the gas when the blast occurred.

MULTAN, Pakistan — Pakistan’s prime minister cut short a trip abroad to rush to the side of victims of a massive fuel tanker fire as authorities on Monday raised the death toll from the blaze to 157.

The truck, carrying some 6,600 gallons of gasoline, was traveling from the southern port city of Karachi to Lahore, when the driver lost control and crashed on a highway.

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 had exploded, engulfing people in flames as they screamed in terror.

The scope of the tragedy was a first in Pakistan but in cases of massive oil leaks in impoverished countries, many of the poorest and least educated often rush to the scene to collect the spilled fuel, unaware of the grave danger they face. Such incidents have been reported in Nigeria and Sudan.