High-tech gear detected "signs of life" Monday at the site of an elementary school buried under mud that swept down a hillside soaked by rain in the eastern Philippines, the provincial governor said.

Sounds of scratching and a rhythmic tapping were picked up by seismic sensors and sound-detection gear brought in by U.S. and Malaysian forces, said South Leyte Gov. Rosette Lerias. Generator-powered lights were set up to allow teams of rescue workers to dig through the sludge during the night.

"To me, that's more than enough reason to smile and be happy," Lerias said. "The adrenaline is high ... now that we have seen increasing signs of life."

The search for survivors in the farming village of Guinsaugon had focused on the school because of unconfirmed reports that some of the 250-300 children and teachers believed trapped inside may have sent cell phone text messages to relatives soon after Friday's disaster.

No survivors had been found by Monday night, said U.S. Marine Capt. Burrell Parmer, who spoke to Marines at the site. Most of the 1,800 villagers were feared buried under the earth, boulders and trees that thundered down a rain-drenched mountain. A few survivors were pulled out in the first hours after the disaster.

Rescuers said the noises might have come from shifting and settling mud covering the school. But the discovery offered a glimmer of hope to rescuers who had all but abandoned expectations of finding anyone alive.

"We know there's something down there," said U.S. Marine Lt. Richard Neikirk, pointing to a spot under a big boulder, where seismic sensors detected sounds. "The farther down we went, the signals grew stronger."

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."

Workers were digging in two places. One — where the sounds were heard — is believed to be the original site of the school, close to the mountain that collapsed. The other is 200 yards down the hill, where the landslide could have carried the building.

There was no visible sign of the school, believed to be under some 115 feet of muck. Philippine Lt. Col. Raul Farnacio said teams had dug about half way down.

Dozens of U.S. Marines and Philippine soldiers, along with local miners, were digging in a watery spot, using shovels on the muck and moving it with body bags, while draining the murky fluid with large water bottles.

They deployed nine seismic sensors that can detect vibrations underground. With everyone standing still, one man used a steel bar to hit on a rock several times and waited for any kind of response from beneath the mud.

Four sensors detected some noise or vibration, but the men could not tell what it was. Rescuers radioed for water pumps and floodlights to keep working through the night.

A 15-man Malaysian team using sensor gear called Delsar employed similar techniques. Five Taiwanese, who brought heat-sensing equipment, were also checking for signs of life. A sniffer dog stopped three times at one spot near the digging.

In new international pledges of aid, South Korea said it would send $1 million, and New Zealand promised to give $133,000. Australia offered engineers to help assess the damage.

Rescuers have pulled out 76 bodies, but estimates varied on the number of survivors and people missing. Lerias said Monday that 928 were missing. National disaster officials in Manila said the number of missing was 1,350, including 246 schoolchildren. Official have reported between 20 to 57 survivors. There was no immediate explanation for the discrepancies.

The search has been a painstaking process slowed by rain, shifting earth and fears of fresh landslides. Officials discussed turning the farming town of Guinsaugon into a massive cemetery, similar to other Asian areas ravaged by the 2004 tsunami.

Trapped survivors of past landslides or earthquakes have sometimes held out for days, communicating with search parties by calling out or tapping on rocks.

But hopes of finding people alive in Guinsaugon have seemed remote because the village was inundated by a dense wall of mud and rock, making it unlikely that many air pockets would form beneath the sodden surface.

Spain's canine association sent three dogs to join those already at the scene.

With no one left to claim the dead and bodies quickly starting to decompose in the tropical heat, victims were being buried in mass graves.

On Sunday, a Roman Catholic priest sprinkled holy water on 30 bodies laying side by side in a mass grave, some wrapped in bags, others in cheap wooden coffins, then said a prayer through a mask worn to filter out the stench.

The only witnesses were local health officials, the provincial governor, some of her staff and a few nearby residents. None knew the victims.

Two shiploads of U.S. Marines, diverted from joint military exercises elsewhere in the Philippines, joined rescue efforts Sunday. Helicopters ferried men and supplies to the site, and Marines surveyed roads and bridges to see if they could support the weight of heavy military vehicles and equipment.