The outbreak began more than a week ago among Manobo tribesmen in an isolated area on the island of Mindanao, said Marilou Geturbos of the Philippine National Red Cross.
"Many of the victims were not immediately given first-aid treatment because of the inaccessibility of the place," said Geturbos, adding that most of the fatalities were children.
She said the Red Cross initially went to the part of Palimbang town affected to check on reports that villagers were dying of starvation.
"We found out that the victims were afflicted with cholera," Geturbos said.
The Health Department in Manila said it was still checking on the reports of a cholera outbreak.