Hunger is worsening in drought-ravaged southern Madagascar, where the number of people in need has tripled in a matter of months, the UN's food agency said Friday.

The World Food Programme (WFP) said three consecutive years of drought had pushed half of the region's population, or 1.5 million people, into "crisis" or “emergency" hunger conditions.

"The number of people in need is three times what was projected mid-year,”it said. "The situation is extremely worrying.”

The island nation already has one of the world's highest rates of stunted growth among children, the result of chronic malnutrition.

In Amboasary, the hardest-hit area, three-quarters of children had by last month dropped out of school to help their parents look for food, the WFP said.