RANAU (Sabah) - Malaysia's Sabah state has put the army on guard as tonnes of debris choking the Liwagu River pose a threat to villagers.

Uprooted trees and rocks, among other debris, are stuck at two points along the river, and the authorities fear one more surge upstream would result in the floating debris pummelling down and endangering the lives of the 3,000 residents in five villages below.

With private contractors being slow in clearing the debris, the Sabah government has got the army to step in. The Fire and Rescue Department is doing its part by evacuating villagers.

Sabah Deputy Chief Minister Joseph Pairin Kitingan said the heavy debris, which also included logs, was lodged at the Ranau Water Department's two water intake points in Kampung Bambagan and Kampung Kimolihing.

"We need help from the army to clear it quickly before another downpour on the mountain pushes it down," he said, adding that contractors may take up to two months to do the job.

The debris has "choked" Ranau's water treatment plant, triggering a water crisis for the 95,000 people in the district. Water tankers from across Sabah have been mobilised to distribute water to villagers. A social media appeal for drinking water for the affected areas has had overwhelming response, with collection centres filling up with donated water.

On Monday, a massive mudflow and boulders and rocks blocked roads leading into Kiau and Mesilau.

Universiti Malaysia Sabah geologist Felix Tongkul said the debris was carried downstream to the Liwagu River. As the surge headed downstream, it caused more trees to fall and the debris field increased, choking the water treatment plant's sluice gates, he said during a visit on Wednesday.

Teacher Haili Salim, who had hoped to move into his new house with his wife and six children in time for Hari Raya, had his hopes dashed when the river bank it was being built on was completely eroded by the mudflow, washing away the house.

"The hard-earned money and sweat we put into building this house has now amounted to nothing," said the 48-year-old. "I have to accept that our house is now in the river."

Hundreds of villagers in Kampung Mesilau have fled their houses. Almost 1,000 people have moved into seven evacuation centres.

Meanwhile, a 4.0-magnitude earthquake hit Ranau at 5.58am yesterday.

THE STAR/ASIA NEWS NETWORK