Severe floods caused by monsoon rains have killed more than 30 people and displaced tens of thousands in Malaysia and southern Thailand, with both countries preparing shelters and evacuation plans in anticipation of more heavy rain.

KUALA LUMPUR/BANGKOK (Reuters) - Malaysia and Thailand are facing a second wave of heavy rain and potential flooding this week, authorities said on Monday, even as some displaced residents were able to return home and the worst floods in decades began receding in some areas.

In South Thailand, over 600,000 households have been affected by the relentless downpours and flash floods. The lives of 12 people have tragically been lost, and thousands of residents have been forced to evacuate their homes and seek refuge in temporary shelters.

With tens of thousands already displaced, both countries set up shelters in anticipation of further downpours.

The death toll from devastating floods in Thailand and Malaysia jumped to 31 on Tuesday as authorities in both countries are bracing for another spell of heavy rains in the coming days.

At least 13 people died and tens of thousands evacuated in one of the worst floods in decades to batter southern Thailand and northern Malaysia.

There are worries in Malaysia and neighbouring Thailand that disastrous flooding could get worse as more rain comes.

Severe floods caused by monsoon rains killed more than 30 people and displaced tens of thousands in Malaysia and southern Thailand, officials said Tuesday,

The floods also submerged large tracts of rice fields, causing millions of dollars in losses to farmers, officials said. The heavy downpour also damaged roads, houses and public facilities in Kelantan and other parts of Malaysia.