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.

At least 12 people have died and more than 600,000 households have been affected by the worst flooding in southern Thailand in decades, according to a government agency. The heavy downpours and flash floods that have persisted across the country’s south since Nov 22 have affected about 640,