Millions of people face severe hunger in the Horn of Africa as the worst drought in more than 40 years could extend to a fifth consecutive failed rainy season, the United Nations and humanitarian agencies warned on Tuesday.

The March-May rainy season appears likely to be the driest on record, devastating livelihoods and deepening a humanitarian emergency in Ethiopia, Somalia and parts of Kenya, including a risk of famine in Somalia, they said in a joint statement.

There is a risk that the October-December rainy season could also fail.

Drought has combined with a global rise in food and fuel prices, pushed up by war in Ukraine, to impact millions of people across the continent.

An estimated 16.7 million people currently face acute food insecurity in east Africa and that figure could increase to 20 million by September, the statement said.

“The threat of starvation looms in east Africa. This is after four failed rainy reasons,” said Clare Nullis, spokesperson at the World Meteorological Organization.

“We are particularly concerned that the situation is set to get worse,” she told a briefing in Geneva.

Aid agencies are seeking to avoid the repeat of a famine a decade ago that killed hundreds of thousands of people.

A rapid scaling up of actions is needed now to save lives and avert starvation and death,” the U.N. and agencies said in the joint statement.

“However, current appeals to respond to the drought remain well underfunded.”