GUINSAUGON, Philippines — The sounds were tantalizing. Scratching and rhythmic tapping. And the farther rescuers descended into the wet muck, the louder they became.
Nearly four days after a mountainside collapsed and covered this farming village in up to 100 feet of mud, seismic sensors and sound-detection gear brought in by U.S. and Malaysian forces picked up what officials hoped were cries for help deep inside a buried elementary school.
"To me, that's more than enough reason to smile and be happy," South Leyte Gov. Rosette Lerias said Monday. "The adrenaline is high . . . now that we have seen increasing signs of life."
Still, it was hard to imagine there were survivors. No one has been pulled out alive since just a few hours after the Friday morning landslide, which killed up to 1,000 people.
U.S. Marine Capt. Mark Paolicelli said Marines left the school site overnight because geologists warned them that heavy rains and danger of mudslides made the area unsafe.
The search has focused on the school because of unconfirmed reports that some of the 250-300 children and teachers may have sent cell phone text messages to relatives soon after the disaster.
Under the glare of generator-powered lights, a multinational group of troops and technicians used high-tech gear like seismic sensors and sound- and heat-detection equipment alongside shovels and rescue dogs.
A U.S. military spokesman said late Monday that U.S. Marines digging at the site had found bodies but no survivors.
"I asked had they received or found any type of survivors, and the answer was no," U.S. Marine Capt. Burrell Parmer said after speaking to the commander of U.S. forces at the disaster site.
The statement discounted an earlier report by Philippine Interior Undersecretary Marius Corpus that U.S. Marines had found 50 survivors. There was no immediate explanation for how the false report had spread.
"There is a lot of rubble, a lot of large boulders," Parmer said. "On some sides near the river, it's very moist, very soft soil, and you can get stuck up to . . . your waistline if you're not careful."
Still, the Marines were eager to discover the origin of sounds detected by seismic sensors.
"The farther down we went, the signals grew stronger," U.S. Marine Lt. Richard Neikirk said as he pointed to a spot under a big boulder.
A Malaysian team using sound-detection gear picked up noises, too.
"We have a sound," said Sahar Yunos of the Malaysia Disaster and Rescue Team. "Knocking, something like that."
A rescue dog also stopped three times at one spot away from where rescue workers were digging.
There was no visible sign of the school. Rescue workers were digging at two places — one where the school was believed to have sat close to the mountain, the other 200 yards down the hill, where the landslide could have carried it.
Dozens of U.S. Marines and Philippine soldiers, along with local miners, were digging in a watery, boulder-strewn spot around the school's original site, using shovels on the muck and moving it with body bags, while draining the murky water in large bottles.
The search was a painstaking process as the crews went yard by yard. At one of the highest points, local troops planted a Philippine flag.
The Marines were from the five-man Third Intelligence Ground Sensor platoon, accompanied by 15 armed Marines.
They deployed nine seismic sensors that can detect vibrations underground. With everyone standing still, one man then used a steel bar to hit on a rock several times and waited for any kind of response underground.
Four sensors detected some "noise" or vibration, but the men could not tell what it was.
They were followed by the 15-man Malaysian team using sensor gear called Delsar and employing similar techniques.
Five Taiwanese, who brought heat-imaging equipment, arrived to check for signs of life, too. Rescuers radioed for water pumps and floodlights to continue working after dark.
President Bush called Philippines President Gloria Macapagal Arroyo Monday to express sympathy for the disaster.
"The president offered our sincerest condolences over the loss of life," his press secretary, Scott McClellan, told reporters as the president traveled to the Midwest to make a policy speech on energy issues.
Some officials were talking about leaving the village as a massive cemetery, similar to tsunami-ravaged areas elsewhere in Southeast Asia where digging out bodies was simply too difficult and dangerous. With no one left to claim them, unidentified bodies already are being buried in mass graves.
"We will still search continuously, but we should be prepared that . . . you're going to have a mass grave right there," said Sen. Richard Gordon, chairman of the Philippine Red Cross. "How can you retrieve those who were buried so deep?"
Philippine military officials had feared 1,800 people, virtually the entire population of Guinsaugon, died. But Gov. Lerias said Monday that 82 people were confirmed dead and 928 were missing.
Official figures of how many survivors were pulled from the mud on Friday have also differed, with counts ranging from 20 to 57.
Contributing: Hrvoje Hranjski