Rescue teams dug on Friday through the rubble of buildings shattered by an earthquake in the Indonesian port of Padang for people feared trapped and the United Nations said more than 1,000 had been killed, according to Reuters.
Aid to thousands of displaced survivors started trickling in, but rescue operations in and around the West Sumatran capital of 900,000 have been hampered by power blackouts and a lack of heavy equipment to shift fallen masonry.
The United Nations humanitarian chief, John Holmes, told a news conference at U.N. Headquarters in New York that some 1,100 people had been killed in Wednesday's 7.6 magnitude quake.
Thousands more were feared trapped under damaged houses, hospitals, hotels and schools, Holmes said.
Telephone links to the disaster zone remained patchy, making it hard to determine the extent of destruction and loss of life.
A social ministry official on Thursday put the number of confirmed deaths at 529, although authorities expect this to go far higher, possibly into the thousands.
The national disaster management center said 2,181 people had been injured and 2,650 buildings damaged.
Australia, South Korea and Japan were among nations offering help.
Workers rigged up floodlights overnight and brought in a giant excavator to try to make their way to students trapped in a three-storey school that had collapsed. Sixty schoolchildren had been attending extra-curricular lessons when the quake struck, the Jakarta Post reported.