Madagascar's death toll from Tropical Cyclone Batsirai rose to 111 Friday, with most of the fatalities from a single district where it levelled homes.

The national disaster management agency BNGRC said 87 people had died in Ikongo district, near the east coast of the Indian Ocean island.

About 30,000 people were living in emergency shelters after Batsirai struck last weekend, the agency said in an updated fact sheet.

Aid agencies are worried about ensuring clean drinking water, and have begun setting up purification systems. Water-borne diseases pose a major health risk after tropical storms.

Madagascar is one of the poorest countries in the world. Some 42 percent of children suffer from chronic malnutrition, even without a natural disaster.