Floods across the island of Madagascar has killed at least 12 people this week, with 18 missing, after unseasonably heavy rain, the national disaster office said on Thursday.

Parts of Africa have experienced heavy rain in recent months because the Indian Ocean is warmer than usual, partly as result of a cyclical weather phenomenon and partly because oceans are warming everywhere.

Floods, landslides and a cyclone killed more than 1,200 people across East and Southern Africa last year, according to a Save the Children count based on U.N. and government figures.

Flooding also displaced nearly half a million people in Southern Sudan, 200,000 in Ethiopia and at least 370,000 in Somalia last year, the United Nations said.