Floods have swept through Thailand, Malaysia and Indonesia leaving more than 50 people dead in some of the worst flooding to hit South-East Asia in years.
In Thailand the death toll has climbed to 33, while in Indonesia at least 23 people were killed and more than 20 were missing, according to officials.
At least one person has died in Malaysia.
"There have been 33 deaths across seven provinces," Thai government spokesperson Siripong Angkasakulkiat said in Bangkok.
"Causes of death include being swept away by currents, drowning, electrocution, and landslides."
Three days of torrential rain that started last week dumped record volumes on Hat Yai, Thailand's southern commercial hub, flooding hospitals and stranding thousands on rooftops.
The city received 335 mm of rain last Friday — its highest in a single day for 300 years.
The Thai military has mobilised about 200 boats, 20 helicopters and its lone aircraft carrier to deliver critical supplies such as oxygen tanks, and to evacuate the sick.
Thai authorities said they had received appeals for help from around 77,000 people via social media.
Floods have affected more than 980,000 homes and over 2.7 million people in Thailand, the interior ministry said.
The weather system had moved towards the Strait of Malacca and intensified into a tropical cyclone moving towards Indonesia, the Thai Meteorological Department said.
Landslides, flash floods cause dozens of deaths in Sumatra
Rescuers recovered more bodies in the search for dozens of people buried under landslides or swept away after torrential rains unleashed flash floods and triggered landslides on Indonesia's Sumatra island.
The death toll had increased to 23 and more than two dozen people remained missing, officials said on Wednesday.
Rescue teams were struggling to reach affected areas in 11 cities and districts of North Sumatra province after the monsoon rains over the past week caused rivers to burst their banks, tearing through hilly villages as mud, rocks and trees tumbled down, leaving destruction in their wake.
Blackouts and a lack of telecommunications were hampering the search efforts, the National Search and Rescue Agency said in a statement.
Images showed water cascading down rooftops as panicked residents scrambled for safety.
In some areas, flash floods rose rapidly, transforming streets into raging torrents carrying tree trunks and debris.
Sibolga police chief Eddy Inganta said that emergency shelters had been set up.
Authorities urged residents in high-risk zones to evacuate immediately, warning that continued rainfall could trigger more landslides after six landslides in the hilly city flattened 17 houses and a cafe.
"Bad weather, power blackouts and mudslides hampered the rescue operation," Mr Inganta said, adding that access remained limited as rescuers battled harsh conditions.
Floods were also reported in many other provinces in the vast archipelago nation that is home to more than 280 million people, including in Aceh and West Sumatra, where hundreds of houses were flooded, many up to roofs and, main roads were blocked, the disaster agency said.
Heavy seasonal rain from about October to March frequently causes flooding and landslides in Indonesia, an archipelago of 17,000 islands where millions of people live in mountainous areas or near fertile flood plains.
ABC/Wires
