At least three people have been killed and four rescue workers are missing in severe floods in northern states which have forced thousands of people to be evacuated, officials and reports said today.

The rescue workers were swept away by fast currents when the boat they were travelling in overturned in Kedah, the official Bernama news agency said.

"Search and rescue operations for the four are ongoing, their fate is unknown," said a spokesman for the district floods operation centre, adding that the workers were patrolling affected areas when the accident happened.

Police said the confirmed fatalities were a disabled 22-year-old girl who drowned in Terengganu and a five-year-old boy thought to have drowned in a canal in Kelantan on Sunday. His body was found in a rice field some distance away from his father's car, where he had been left several hours earlier.

A six-year-old boy also drowned in Kelantan today after being swept away while playing in flood waters along a road, police told AFP.

Five states affected

Flooding has hit five states - Perlis and Kedah in the north, Kelantan and Terengganu in the northeast and north-central Perak.

Some 11,700 people have been evacuated from Kedah, while 4,548 residents in Perlis and about 100 in Perak have been shifted to relief centres, according to local police and Bernama.

Kangar, the capital of Perlis and one of the worst-hit areas, was also suffering power outages in some areas, while Perlis chief minister Shahidan Kassim said two-thirds of the state was under water.

But the situation eased this afternoon in Terengganu and Kelantan, with flood waters receding while two-thirds of some 5,400 Terengganu evacuees returned to their homes.

Tropical storm warning

Deputy Prime Minister Najib Razak, touring flood-affected areas late today, pledged aid to Perlis, Kedah, Terengganu and Kelantan.

He also said flood waters in Kedah and Perlis had affected some 25,000 hectares of rice fields run by the federal government and estimated damage at RM39 million, Bernama reported.

The meteorological services department issued a tropical storm warning on Sunday after detecting a depression over the South China Sea, and said strong winds and rough seas were expected to persist until Tuesday.

Train services connecting the north to Thailand were disrupted by the floodwaters, which rose to three metres above the track in some areas.

Workers were waiting for levels to drop before repairing a damaged stretch of the line between Kuala Lumpur and Hat Yai in southern Thailand, said Azizah Ujang from national rail company KTMB.