Heavy rain is hampering rescue efforts after last Friday's mudslide in the Philippines, with overnight downpours prompting fears of further landslips.
Rescue teams are faced with a huge wall of mud
"Safety is an ongoing concern," said US Marine Capt Burrell Parmer, who is involved in the operation.
Rescuers are now using seismic sensors in an effort to find survivors.
But hopes of finding anyone alive are fading. Although more than 90 people were confirmed dead, officials say the final death toll could be about 1,000.
The BBC's Andrew Harding, who is at the scene, says the spot where the village of Guinsaugon once stood is a total wasteland.
Efforts have focused on the elementary school where 200 children and 40 teachers were thought to have been trapped. But despite constant digging for the last few days, the mud is so deep that the searchers have yet to reach it.
Signs of life
Rescue teams from at least five countries worked into the night on Monday with sound and heat-detection equipment as well as trained rescue dogs.
But the search teams are unable to work as fast as they want because of fears that large movements could set off further landslides.
US Marine Captain Mark Paolicelli said his men eventually left work overnight because geologists warned them that the area was unsafe due to the heavy rainfall.
The downpour has also reshaped the sea of mud covering the village, and one of the first jobs for rescuers on Tuesday was to build a makeshift bridge to cross a creek that had sprung up overnight.
Rescue teams were buoyed late on Monday by scratching noises that were reportedly heard underground near where they are searching for the school.
They are anxious to know whether these sounds came from survivors or shifting mud and water below the surface.
No more sounds have been heard on Tuesday, and Yaacob Yusuf, a member of the Malaysian team working around the school, admitted that it was difficult to pick up such noises anyway due to the conditions.
"It's really very hard for us because our detectors can catch sound travelling on solid ground or material, but if the ground is soft it's difficult to hear," he said.
As hopes of finding any more survivors diminish, some officials are suggesting leaving the village as a massive cemetery because digging out bodies is difficult and dangerous.
On Monday the Philippine government revised its figures of the number of dead down from 1,800, based on a recent survey showing that Guinsaugon had a population of 1,420.
About 400 villagers were found to have been away from the area at the time of the landslide.
Many residents had left when the heavy rains began, fearing landslides. But some had returned as the weather improved, despite warnings.