PADANG, Indonesia — An earthquake survivor trapped in a collapsed hotel in western Indonesia sent a text message saying he and some others were alive, triggering a frantic rescue operation, but hopes faded Saturday as sniffer dogs failed to detect life.

Officials said voices and claps had been heard from survivors buried in the Ambacang Hotel since Wednesday's 7.6-magnitude quake on Sumatra island. The temblor killed at least 715 people, left more than 3,000 missing and destroyed more than 20,000 houses.

Many of the missing are likely to be dead as search teams find several villages in the outlying hills wiped off the map by landslides caused by the quake, news reports said.

MetroTV showed aerial footage of the effects of a landslide — uprooted trees and a large empty area of brown earth where a village once stood. The houses apparently had been buried under tons of mud, rock and debris rolling down from a hillside. The broadcast did not identify the village.

The Detik.com news Web site quoted Rustam Pakaya, a Health Ministry official, as saying that in Pulau Aik village, "all the houses seem to have been swallowed by earth."

"Even the mosque minaret is not visible," Pakaya said.

El-Mostafa Benlamlih, the U.N.'s humanitarian coordinator for Indonesia, said he had received preliminary information about 200 houses being swept away in Pulau Aik, but could not say if that constituted the entire village. He also had no information about casualties.

He said 3,000 people are missing just in Padang, the region's main city, and the total figure for Sumatra could be higher.

Immediate medical needs were being met, but aid efforts are "still concentrated in Padang area," with outlying areas still short of aid, Benlamlih said.

He said aid agencies would focus on restoring public utilities, sanitation and preventing disease.

The search for the hotel survivor — staying in Room 338 — started after he sent a text message to relatives Friday saying he and some others were still alive.

But after more than six hours of searching, Padang police chief Col. Boy Rafli Amar told reporters, "So far rescuers have found nothing."

As he spoke, rescuers used backhoes and drills to try to break a passage through thick slabs of concrete in the six-story Ambacang Hotel.