Hanoi  - Vietnam's death toll from typhoon Ketsana has risen to 101, with 24 more people reported missing, national storm and flood authorities said Friday.

Among the dead was an army lieutenant colonel killed when his boat capsized while he attempted to rescue flood victims.

Some of the worst loss of life came not in the coastal regions, but in mountainous highland areas as the storm moved inland, bringing flash floods and mudslides. Thirty people were reported killed in the Central Highlands province of Kon Tum, mostly due to landslides.

Vietnamese Prime Minister Nguyen Tan Dung visited flooded areas on Thursday to encourage local authorities in the search for the missing. Two reservoirs in Kon Tum are reported at risk of breaching, threatening thousands of people living downstream.

Dung said some 600,000 people had been evacuated to safety, including 300 Cambodians in border regions. Cambodian Prime Minister Hun Sen phoned Dung to thank him for Vietnam's help.

The typhoon brought winds of 117 kilometres per hour (kph) when it came ashore in the central province of Quang Nam, and dumped up to 900 millimetres of rain. More than 6,000 houses were destroyed by floods, wind or landslides, along with dozens of schools and health care centres.

There were reports of 116 fishing boats sunk. More than 17,000 hectares of rice were submerged, and 107,000 poultry were reported killed.

Vietnamese flood and storm authorities estimated Friday the storm had caused some 600 million dollars in damage.

In the city of Danang, the typhoon caused a pipeline to rupture at a petrol storage depot, attracting hundreds of people who scooped up the loose fuel, the Vietnam News reported.

Streets in many towns, including the historic tourist centre of Hoi An, remain flooded. Vietnam's sole oil refinery at Dung Quat, damaged by power outages, has not yet resumed operations.

Vietnam's national weather centre said Friday that river levels were gradually declining, but warned of continued potential for flooding and landslides.

Ketsana killed at least 277 people when it struck the Philippines over the weekend, causing estimated damage of 100 million dollars.

Vietnamese weather authorities reported Friday that two more storms have formed in the Pacific Ocean since Ketsana dissipated.

The 101 deaths caused by Ketsana brought Vietnam's death toll from natural disasters to at least 242 so far this year.

In 2008, natural disasters killed 550 people in Vietnam and caused damage amounting to more than 700 million dollars. (dpa)