But while rescue efforts are still concentrated in Padang, there are serious concerns that it may be too late to save most of those missing, presumed trapped beneath the city's collapsed concrete buildings.
Instead the focus is shifting to emerging stories of widespread destruction in areas outside the city.
At least 600 people are believed to be missing in villages north of Padang.
"All the houses seem to have been swallowed by earth," a health ministry official in the village of Pulau Aik told the Associated Press.
Villagers contacted by reporters told of hundreds of people missing in each settlement.
"In my village, 75 people were buried. There are about 300 people missing from this whole area. We need tents and excavators to get the bodies but the roads are cut off," one villager, Ogi Martapela, told Reuters.
WEST SUMATRA QUAKES
First quake struck on Wednesday at 1716 local (1016 GMT) under sea north-west of Padang
One Red Cross worker, Testos, told Reuters his team needed medicines, drinking water and clothes to take to those left homeless by the quake.
But access to these areas remains difficult, and few details are known yet of the extent of the destruction or the loss of life.
Local TV stations have begun to reach some of the affected areas, broadcasting images of villages reduced to rubble and tales of villagers without access to clean water.
"We have not received a thing. We need food, clothes, blankets, milk. It seems like the government has forgotten about us," Reuters quoted one woman, Siti Armaini, as saying in Pariaman, 40km (25 miles) north of Padang.
In Padang, witnesses report that the stench of decomposing bodies now hangs over collapsed buildings as rescuers battle to reach survivors.
Aerial views of some of the devastation caused by the quake in Sumatra
At the collapsed wreckage of a hotel, rescuers worked frantically on Saturday to find any of eight people thought to have survived Wednesday's earthquake.
One person trapped in the ruins of the Ambacang Hotel sent a text message to a relative on Friday asking for help, rescuers revealed.
Those trapped were believed to be on what was the 6th floor. But by mid-afternoon in Padang none of the eight had been located.
The head of a Japanese search and rescue team said his men and dogs had found "no signs of life".
"Our dogs are trained to smell for living people, not the dead, and they didn't sense anything," Hidehiro Murase told AP.
Specialist teams from around the world have begun arriving at co-ordination centres in Padang, waiting to be deployed to the field.
The Red Cross planned to hold a meeting in the city on Saturday to co-ordinate relief efforts.
The priority is to ensure injured survivors receive the medical attention they needed, Red Cross officials say.
Two Australian planes carrying medical personnel and rescue experts have arrived in Padang, with dozens of British firefighters - delayed for 24 hours by a broken-down plane - due to join a 16-man charity deployment late on Saturday.
As well as the Japanese, a Swiss sniffer-dog team is already on the ground, and Russian and Estonian personnel have all been sent. Countries around the world have pledged relief funds.
Indonesian President Susilo Bambang Yudhoyono has also called for $10m (£6.2m) in government aid to be distributed quickly.
"The... fund has to flow quickly, no more bureaucracy for this," he said. "This is an emergency, so speed is crucial."
Wednesday's 7.6-magnitude quake struck off the coast of Padang and caused devastation. A second quake of 6.8 struck nearby on Thursday causing panic but no reports of damage or casualties.
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