Up to a quarter of children in parts of Chad are facing acute hunger despite an easing of the overall famine threat across the Sahel region of Africa, UNICEF warned on Friday, calling on donors to provide more funds.

Aid groups have been warning for months that failed rains were leading to a food crisis in the strip of land below the Sahara desert that includes Mauritania, Chad, Niger, Mali, Burkina Faso and northern Nigeria.

While an all-out famine appears to have been averted, the U.N. agency said a nutrition survey carried out with the Chadian government showed between 15.2 and 24.9 percent of children were suffering acute malnutrition depending on where they lived.

These latest figures prove that families have been experiencing a severe reduction in their ability to cope and fend for themselves, said the UNICEF Representative in Chad, Marzio Babille.

We appeal to donors to make up the $8 million shortfall, Babille said of an appeal made for a total $19 million earlier this year, adding that the extra money was needed to support 50,000 of the most vulnerable children.

An acute malnutrition rate of 15 percent is defined by the World Health Organization as an emergency.

Recent abundant rains in Chad have prompted hopes of a good harvest in coming weeks, but the impact of this year's drought will lead to new difficulties in the Sahel next year because farmers had to deplete cereal stocks to feed their livestock.

Chad and neighboring Niger were at the center of food shortages this year that threatened 10 million people across a region which has always been prone to drought.

While in Niger the shortages were seen worse than at the last emergency in 2005, the United Nations said the country was better prepared to deal with it than five years ago, when then President Mamadou Tandja played down the scale of the problem.

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