At least two people are dead and more than 60,000 have fled their homes after floods triggered by torrential rains engulfed whole towns and villages in five states.

The bodies of two men were found in Segamat district in southern Johor state, the area worst hit by heavy monsoon rains, said Che Moin Umar, head of disaster management at the Civil Defence Department.

A third body in Johor's Kota Tinggi district was still being identified and a cause of death being determined, he said.

"Two people have died already due to the floods ... The younger man's body was discovered yesterday, while the body of the second victim, a 70-year-old man, was found today in Segamat," Che Moin told AFP .

He said the elderly man could not escape the flood waters that rushed through his village because he was partially paralysed by a stroke.

"The currents are very strong this year, and in Johor it is (so) tremendous that even the rescuers on boats are having difficulty navigating the current," he said.

Che Moin said the number of evacuees on Thursday had risen to 63,616 - 54,585 people from Johor and a further 10,031 displaced in the neighbouring states of Malacca, Negeri Sembilan, Pahang and Kelantan.

Full assistance

Deputy Prime Minister Najib Razak, who visited flood victims in Johor yesterday pledged full assistance from the government, the state Bernama news agency said.

"We will extend all aid needed to help the flood victims in Johor, (and) if not enough, more will be dispatched," Najib was quoted as saying.

Health authorities said they had stepped up vigilance to prevent outbreaks of waterborne diseases in relief centres across the affected states, where thousands of evacuees were camped out.

"We have dispatched our health teams to oversee the sanitation especially at the evacuation centres," the health ministry's director of disease control, said Ramlee Rahmat.

"Definitely we are most concerned about the possibility of the spread of cholera and we are monitoring the standards of hygiene," he said.

The floods have also triggered mudslides, forcing road closures and the suspension of east- and south-bound rail services, including to Singapore.

Parts of Johor has recorded rainfall of up to 66.3 centimetres, with an average of 40 centimetres throughout the state. A daily reading above 20 centimetres is deemed high.

The Meteorological Department on Thursday said rains were expected to continue until the weekend.