A week after giant waves swamped parts of the provincial capital, Banda Aceh, on the northern tip of Sumatra island, the water is only just beginning to drain off to reveal the full extent of the horrific destruction and yet more bodies to count.

"I've never seen anything like this. We've seen bodies 20 miles out to sea. You just cannot describe it," said Capt. Larry Burt, commander of a helicopter air wing on the US aircraft carrier Abraham Lincoln parked off the Sumatra coast.

"Above the water line, there are people standing there waving flags trying to signal us. There are so many, you just can't stop for all of them," he told Reuters after a mission down the west coast, which bore the brunt of the December 26 quake and tsunami.

Walking the streets of Banda Aceh yesterday, local clean-up crews and exhausted soldiers find it hard to know where to start, their efforts hampered by a steady drizzle.

Fires burn around the clock to clear areas around Banda Aceh's main parade ground of wooden debris. The soggy ground, about the size of five football fields, is stacked with rubbish, smashed vehicles and badly decomposed bodies.

As water drains from many districts of this city of more than 300,000 people, a nightmarish landscape of sludge, flattened homes and tangled corpses is exposed. The stench is overpowering.

"We need so much help," said Hayaddin, 51, a street vendor. "People say more waves will come."

Again during the long night, aftershocks from the massive quake that triggered the killer wall of water could be felt, sending panicked residents fleeing into the streets.

Zurhan, 23, a bulldozer driver, wearing a woolen jumper over his head to filter out some of the smell of death, stood in the middle of the parade ground shaking his head.

As many as 30,000, of the roughly 80,000 Acehnese known to have died, perished in this city when the waves, triggered by the world's most powerful earthquake in 40 years, swept through.

With most of the population suffering severe trauma, half a dozen mechanical excavators sat idle on the backs of trucks, authorities unable to find drivers for them.

Substantial help has finally begun reaching refugees in some of the more remote parts of Aceh and the US military has arrived in force, parking a flotilla of ships off the coast.

"This is an enormous human tragedy. The biggest problem right now is water ... It's poisoned," Jorgen Poulsen, chief of the Danish Red Cross, said.

"We hope we can avoid cholera. The problem is we have already seen people vomiting in town."

Indonesian soldiers in rubber boats, armed with black plastic sheets, prepared to remove bodies clogging a canal.