The bodies of 39 women and 36 men have so far been found in this shattered North Sumatra resort town, said disaster relief coordinator Bonar Pasaribu.

The number reported missing has risen to 100, he said.

"We will try our hardest to find these people but the chance of them being alive is slim to none," he said.

Two German women aged 20 and 26, a 63-year-old Singaporean male, a 30-year-old Dutchman and another 30-year-old man from Austria were among those killed when the flash floods smashed into the town on the banks of the Bahorok river late Sunday.

Along with the surging floodwaters came hundreds of logs, felled on the slopes of nearby Mount Leuser and washed down the river. They smashed into scores of homes as well as resort cottages on the riverbank.

Hundreds of Brimob paramilitary police and troops used chainsaws to clear logs and heavy equipment to remove motorbikes, cars and other debris, as the smell of rotting corpses hung faintly in the air.

Langkat district chief Syamsul Arifin said Monday the flood was caused by illegal logging inside the neighbouring Gunung Leuser national park and described it as a disaster waiting to happen.

"We know who the bosses and the thieves are. The victims are not only the environment but also humans. We have predicted this," Arifin said.

Bahorok, 96 kilometres (60 miles) northwest of Medan, is on the eastern fringes of the park. It is the home of a famed orangutan refuge, which is popular with tourists who also go trekking and white-water rafting.

A disaster relief official, who declined to be named, said the logs caused much of the devastation, smashing into tin-roofed thatched huts and concrete structures alike.

"This region is very seriously damaged" by random logging, said Longgena Ginting, executive director of environmental group Walhi.

Severe flooding and landslides, often blamed on rampant deforestation, are common during Indonesia's rainy season. Residents said Bahorok was hit by floods every year but had never experienced anything like this week's devastation.

Headscarved women in the town sobbed quietly as they waited for news of loved ones.

Nur Rahma, 35, saw three of her children, aged between 18 months and six, swept away. "I still hope my children are alive. I will keep looking till their bodies are found," she said, weeping.

Bodies were laid out in a mosque courtyard before being taken to a morgue in Medan. The injured were taken to hospital in the town of Binjai.

Eight foreigners who escaped the deluge were evacuated to Medan and Binjai.

Some, like Californians Tom Donelly and Tyson Murphy, had miraculous escapes.

"We were asleep when the flash floods hit our room," Donelly, 26, told AFP.

"We were up to our necks and then we were swept out of our room but we managed to grab two trees and climbed up them.

"We were the luckiest people in the world."

TERRA.WIRE