More than 4,100 people have died in Indonesia after tidal waves and flooding were triggered by a huge earthquake on Sunday.
Aceh's streets were flooded with water after the waves hit
Officials said the worst hit area was Aceh province, which lies closest to the earthquake's epicentre.
But the flooding, and poor communications in the region, meant it could be some time before the true extent of the damage becomes clear.
Reports from Aceh tell of bodies being found in the tops of trees.
The earthquake hit about 100km (65 miles) off the northern coast of the Indonesian island of Sumatra, and there are reports of serious damage to buildings in the capital of Aceh, Banda Aceh.
But most of the deaths are believed to have been caused by flooding in the wake of tidal waves triggered by the quake.
Mustofa Gelanggang, the head of
Aceh's Bireuen district, said settlements on the coast had been badly hit.
on stilts and made of wood, were either swept away or destroyed. Some areas were under between two and three meters of water for
about two hours," he said.
Indonesian health ministry officials said late on Sunday that 4,185 people had died in the wake of the tidal waves, with the worst-affected areas around Banda Aceh.
Indonesia's President Susilo Bambang Yudhoyono has declared a state of national disaster.
The BBC's Jakarta correspondent, Rachel Harvey, says that as flood waters recede, more bodies are being found.
One additional problem is that Aceh has been closed off to journalists and aid workers for over a year because of military action against separatist rebels.
Getting more information from the region, and getting aid into it, will be made more difficult, she says.
Our correspondent says there is particular concern about the south-western coast of Sumatra island, after officials failed to make contact with the area.