MEXICO CITY, Mexico - The death toll in Friday night's pipeline explosion in Mexico continues to rise and is now at 73.

Rescuers are still pouring through rubble amidst dozens of charred bodies and wreckage.

The blast is believed to have been caused by thieves trying to syphon fuel from the pipeline. When they drilled into and ruptured the pipeline, an explosion occurred.

The blast took place on Friday night in the town of Tlahuelilpan, in Hidalgo state. The inferno that followed took several hours to extinguish. It was finally put out just before midnight.

As at Sunday the death toll stood at seventy three, but is likely to rise further as many of the scores that have been injured are in critical condition. Original reports said that 21 had died. This was revised to sixty six on Saturday, but by Sunday the toll had worsened to 73.

Hidalgo Governor Omar Fayad confiremd the latest figure on Sunday. Flanking the governor as he delivered the grim news was the newly-installed Mexican President Andres Manuel Lopez Obrador.

Fuel theft is widespread in Mexico due to soaring gas prices. Thousands of marines have been deployed to protect pipelines, which have been losing up to $3 billion a year through fuel theft.

"I urge the entire population not to be complicit in fuel theft," Fayad posted (in Spanish) late Friday night. "Apart from being illegal, it puts your life and those of your families at risk. What happened today in Tlahuelilpan should not be repeated."

On Friday night as events unfolded President Lopez Obrador tweeted: "I'm very sorry for the serious situation in Tlahuelilpan due to a pipeline explosion. I'm in Aguascalientes and since the director of Pemex and the defense secretary briefed me, I gave instructions to contain the fire and treat the victims."