Relief centres in southern Malaysia are reported to be bursting at the seams with more than 100,000 people evacuated from their homes after heavy flooding.
Johor has been hit by floods for a second time in a month
Aid workers have appealed for help as they try to feed and shelter victims in the worst-affected state of Johor.
Major rivers burst their banks, cutting off a number of towns.
The floods came as many were returning home from shelters following the first round of flooding in December that killed at least 17 people.
More than 300 relief centres have been set up on higher ground to shelter the huge number of displaced people.
But relief workers say some centres have been overwhelmed and cannot take in any more evacuees. At least one centre has reportedly run out of rice.
"We need donations of food. Some [relief] centres have no more space already," one official was quoted by the Associated Press as saying.
"Blankets and warm clothing are also needed."
Health officials are also concerned about the risk of water- and mosquito-borne diseases.
Heavy rains deluged Johor, the state that borders Singapore, over the weekend.
One town was almost submerged, with only rooftops standing above water in some areas, local media reported.
More than 1,000 police are reportedly being drafted in to assist with relief efforts and to prevent looting.
Prime Minister Abdullah Ahmad Badawi has said a state of emergency may be declared if the floods worsen.
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