The U.N. humanitarian office reports a more than 20 percent increase in the number of people needing international aid since the start of the year, fueled mainly by hunger in sub-Saharan Africa.

The U.N. Office for the Coordination of Humanitarian Affairs says 62 million people required humanitarian aid as of the end of June, up from 51 million at the start of the year.

OCHA's spokesman Jens Laerke told reporters Friday in Geneva that most of the increase is due to 18 million people facing severe hunger and malnutrition in nine countries in Africa's Sahel region.

He said the situation is made worse by the conflict in northern Mali, where heavily armed extremist Islamists with links to al-Qaida wrested control over a territory the size of France and proclaimed an Islamic state.