BAHAWALPUR, Pakistan — Alerted by an announcement over a mosque’s loudspeaker that an overturned tanker truck had sprung a leak, scores of villagers raced to the scene with fuel containers Sunday to gather the oil. Then the wreck exploded, engulfing people in flames as they screamed in terror.

At least 153 men, women and children were killed, with dozens more in critical condition, hospital and rescue officials said.

“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.”

About 30 motorcycles that villagers had used to rush to the site of the highway accident lay charred nearby along with cars, witnesses said. Local news channels showed black smoke billowing skyward and army helicopters taking away the injured.

As victims cried out for help, residents wandered through the area, looking for loved ones.

Zulkha Bibi searched for her two sons.

“Someone should tell me about my beloved sons. Where are they? Are they alive or are they no longer in this world? Please tell me,” she pleaded.

Many of the dead were burned beyond recognition, said Dr. Mohammad Baqar, a senior rescue official in the area. They will have to be identified through DNA.

The disaster came on the eve of the Muslim holiday of Eid al-Fitr, which marks the end of the fasting month of Ramadan. While Saudi Arabia and most other Muslim countries celebrated the holiday Sunday, Pakistanis will mark it Monday.

The fuel truck was traveling from the port city of Karachi to Lahore, the Punjab provincial capital, when the driver lost control and crashed on a highway outside Bahawalpur.