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.

Authorities say these have been the worst floods in decades, resulting in the death of at least 27 people across the two countries.

The death toll from the worst flooding to hit southern Thailand in decades rose to 22 as several thousand people remained confined to relief camps, and authorities warned of more heavy rain over the next few days.