Rescue workers have now recovered 32 bodies from a bus buried by a landslide in central Mexico and hopes are fading for any other passengers on board.
Between 40 and 60 people, including a group of schoolchildren and teachers, were thought to be aboard.
The bus was travelling on a remote road in Puebla early on Wednesday, after heavy rains, when a mountainside collapsed on top of it.
Hundreds of emergency workers spent the night digging to reach the bus.
State ambulance chief Salvador Bianchini said there were fears the nearby cliff could engulf rescuers but that the search would probably continue on Friday.
The bodies of at least four children were among those pulled from the rubble. All but two of the 32 victims have been identified.
It is not clear exactly how many people were on board the bus bound for Tehuacan, but witnesses said it was full.
A senior state rescue official, German Garcia, told the Reuters news agency that mud and rock as much as 7m (23ft) thick fell on top of the vehicle.
Witness Mario Jimenez told W Radio he was driving behind the bus near the town of Eloxochitlan when he saw huge rocks slide down the mountain.
"The rocks fell first and then it was the dirt," Mr Jimenez said.
Residents of the nearby village of Zacacuapan said they heard the landslide but only realised what had happened when the bus failed to reach the village.
Coffee grower Benito Cortes said he knew most of the victims.
"We got down there and it was all covered up and we realised something had happened because the bus never arrived".
State Governor Mario Marin said the administration would pay for funerals and set up scholarships for the children of the deceased.