Hundreds of rescuers dug frantically Thursday to reach victims of an avalanche that swept down a Mexican mountainside and buried a bus carrying up to 60 passengers. Thirty-two bodies were recovered as hope waned of finding survivors.

Soldiers and rescue workers braved threats of additional slides to pull victims from the bus, which had been traveling along a remote winding road Wednesday morning when a rain-soaked slope gave way near the town of Eloxochitlan in the central state of Puebla.

Officials said the bus was carrying between 40 and 60 people but that it was impossible to know the exact number of passengers on board because the bus made stops along the way.

The state's chief of ambulance services, Salvador Bianchini, told the Televisa television network that "all are dead," but did not explain how he knew that. He said workers had only gained access to a small section of the bus.

Other state officials have declined to speculate on the possibility of survivors.

"The search is very difficult," Bianchini said, noting that officials were concerned a nearby cliff could come tumbling down at any moment, but that the search would probably continue Friday.

The bus was traveling along a remote winding road Wednesday morning when a rain-soaked mountainside gave way near the town of Eloxochitlan in the central state of Puebla.

Puebla government spokesman Ismael Rios said the landslide brought down at least 100 tons of earth and rock piled 130 feet high.

So far, all but two of the 32 victims — aged 6 to 48 — have been identified, Puebla's state government said.

Gov. Mario Marin said officials were bringing coffins to the site, and that the government would pay for victims' funerals and set up scholarships for their children.

Local news media reported that most of the bus passengers were from Eloxochitlan, an extremely poor town in central Mexico.

Weeping relatives of the bus riders and local residents crowded around barriers guarded by soldiers near the site of the landslide, which happened as the bus was headed to the nearby town of Tehuacan.

Eloxochitlan resident Donato Trujillo, who was helping rescue workers, saw the landslide from his home.

"We heard the movement of the earth, a tremendous roar and people screaming," he told Televisa. "It was a direct, fatal blow."

President Felipe Calderon ordered the interior and defense departments to help in the rescue efforts.

Marin, who arrived at the site by helicopter, said no one was to blame for the tragedy.

"All the mountains are risky. ... It's nature," Marin said.

He said authorities are considering dynamiting the rest of the mountain once rescue efforts end to avoid future landslides.

The mountain's "current condition is a great risk," he said.

Heavy rainfall across Mexico this week has triggered flooding and landslides that killed several people.

Fifty-seven people died last year when their overloaded bus careened off a highway into a 200-meter (650-foot) ravine in state of Veracruz, which borders Puebla.