The government lowered its estimated death toll to between 400 and 500 people from an earlier estimate of 1,000; the United Nations, meanwhile, raised its toll to 624.
"There's still no electricity available, and lanterns are in short supply. So many residents are relying on candles for light," says CBS News Reporter Celia Hatton, who visited the island of Nias Thursday, hard hit by Monday night's 8.7-magnitude quake. "Most people are also terrified of sleeping indoors, for fear that aftershocks might topple more buildings, so they're choosing to sleep in makeshift tents."
Survivors said they were going hungry, but in signs of hope, rescuers pulled a 13-year-old girl alive from a collapsed five-story building, and a group of 11 Western surfers missing since the quake were found alive by a search helicopter. A baby girl was also born in a makeshift hospital.
Indonesia's president visited the remote island, which bore the brunt of the earthquake in the same Indian Ocean region where an even-larger quake three months earlier triggered Asia's tsunami catastrophe.
While touring Gunung Sitoli, President Susilo Bambang Yudhoyono and his wife Kristiani Herawati were confronted by two young girls who wept uncontrollably. One said she had lost her siblings while the other said her father died.
Looking distressed, Herawati stroked one child's head and said: "Be patient, we will help you."
Hatton had a similar experience.
"At one point, while walking on the island, we came across some women who were crying loudly and hugging each other in the street," she reports. "We quickly understood why they were so upset: They were standing in front of a Buddhist temple, where the bodies of the earthquake victims were being gathered. The women had lost their mother, and no one could stop their tears."
Gunung Sitoli remained without power and running water Thursday, as islanders and rescuers frantically searched through destroyed buildings for survivors, bodies and belongings. Aftershocks continued to rattle the area.
Under a tarp on the grounds of a mosque, Yusman Gule had no water to mix with his meager dried food, so he fed 6-year-old daughter Yumni with just the powder. She lost an ear, broke an arm and badly squashed her fingers in the quake but still managed to smile.
"Don't leave us here to die," the father said. "It's difficult to find food. All we can do is beg."
Chamsyah pleaded for patience, saying food would arrive later in the day.
"We admit the distribution has been slow," he said later. "We can understand that people are dissatisfied, but thanks be to God the situation is getting better."
On the neighboring island of Simeulue, television images showed collapsed houses, major damage to a port and rescuers painstakingly retrieving a battered body from rubble.
Indonesian workers dug for five hours before pulling a 13-year-old girl from rubble where she had been trapped for 52 hours. She was unhurt apart from some scratches on her foot.
Red Cross official Herri Ansyah said the search for survivors would continue for several days, as it did after the Dec. 26 quake and tsunami. "In Banda Aceh, people were found alive after six days," he said.
The surfers — three Britons, two Swedes, two Canadians, two French, one American and a German — were found on Nias island.
"They're feeling well, considering the circumstances," Swedish Foreign Ministry spokesman Christian Karlsson said. "They've been sleeping outside. ... They've boiled water and food. I'm not sure what they've eaten, but I guess it's coconuts."
The government said so far 279 bodies had been buried and the final toll would likely be between 400 and 500 across the disaster zone. Earlier in the week, the vice president predicted the toll could reach 2,000, and North Sumatra's governor had estimated that 1,000 died.
U.S. State Department spokesman Adam Ereli said U.S. naval ships and medical ships were steaming toward the battered islands.
Monday's quake struck under the sea off the west coast of Indonesia's Sumatra island. December's 9.0-magnitude quake that triggered the tsunami struck further northwest along the Sumatra coast.
The latest earthquake did not produce a tsunami, but villagers close to its epicenter said it did unleash damaging waves.
In Singkil, a town of about 5,000 on the western coast of Sumatra island, a wave up to 6 feet high powered inland up to 200 yards, residents said Thursday, washing away several houses and inundating the port area. It was unclear whether the wave was a tsunami or an unusual tidal surge.