The death toll from widespread floods in Malaysia has risen to six and the number of people evacuated to relief centres increased sharply as heavy rains continued to fall.

A 15-year-old boy is thought to have drowned after he went swimming in a canal in Kelantan, the official Bernama news agency reported.

Bernama on Sunday had reported five dead and three missing in the floods, which have hit three states in the peninsula.

More than 15,000 people in total are now housed in relief centres, compared with about 10,800 on Monday, Bernama said today.

Red alert in Johor, Pahang

As well as Kelantan, the floods have also hit Johor in the south and Pahang in the east.

The meteorological department warned that the torrential downpours will continue until the end of the week as the flood alert for Johor and Pahang remained at the highest level of red after it was raised the previous day.

"During the monsoon season, it's normal to have heavy rains. It will remain the same until the end of the week," deputy science minister Kong Cho Ha told AFP.

A year ago, floods in Johor left more than 110,000 people displaced in a disaster that caused at least RM1.5 billion in damages.