TLAHUELILPAN (Mexico) • An explosion and fire in central Mexico killed at least 79 people after hundreds swarmed to the site of an illegal fuel-line tap to collect petrol amid a government crackdown on fuel theft, officials said.

Health Secretary Jorge Alcocer Varela said yesterday that another 66 people remained hospitalised.

The blast last Friday occurred near Tlahuelilpan, a town of 20,000 people about an hour's drive north of Mexico City.

As soldiers guarded the scene over the weekend, forensic specialists in white suits worked among the blackened corpses - many frozen in the unnatural positions in which they had fallen - and civilians stepped cautiously along searching for missing relatives.

Firefighters and ambulances run by state oil company Pemex had rushed to help victims with burns and take the injured to hospitals.

Last Friday, when the authorities heard that fuel traffickers had punctured the pipeline, an army unit of more than 20 soldiers arrived and attempted to block off the area, said Defence Secretary Luis Crescencio Sandoval. But the soldiers were unable to contain the estimated 700 civilians, including entire families, who had swarmed in to collect the leaking petrol in jerrycans and buckets, according to witnesses.

The soldiers had been moved away from the pipeline to avoid any risk of confrontation with the crowd when the blast occurred, some two hours after the pipeline was breached, said Mr Sandoval.

President Andres Manuel Lopez Obrador, a leftist who took office only weeks ago, travelled to the scene early last Saturday.

He did not fault the soldiers, saying: "The attitude of the army was correct. It is not easy to impose order on a crowd."

But he vowed to continue fighting the growing problem of fuel theft and called on the government to extend aid to those affected.

AGENCE FRANCE-PRESSE, REUTERS