Some 2.5 million people, including at least 800,000 children, are in danger of starvation in the arid country on the southern fringe of the Sahara - one of the most remote reaches of Africa.

Women who have carried their malnourished children across the desert reach an emergency aid centre

Appeals from aid agencies have so far gone largely unheeded. The UN's World Food Programme had a negligible response this year when it asked international donors for £2.5 million.

Now that villagers have started dying, with perhaps 150,000 children facing imminent starvation, the costs of emergency supplies are "sky-rocketing", says Gian Carlo Cirri, the WFP's representative in the capital, Niamey.

"We missed the first train because of late funding and huge procurement problems," he said. "We have no other solution than to ask for a huge amount of money just to save those lives, otherwise we will have a tragedy."