Dozens of people are feared dead after human traffickers abandoned them in Niger's northern desert without food or water, a senior local official said on Monday.
Fatoumi Boudou, the prefect of Niger's northern region of Bilma, told the AFP news agency that authorities on Sunday rescued 24 people who were part of a group of "70 people who had left in three vehicles from Agadez for Libya".
Agadez is a remote town in Niger on the edge of the Sahara desert that has become a major people-smuggling point.
The traffickers "abandoned them in the middle of the desert without food or water", Boudou said, adding that those rescued had spoken of several dead bodies without specifying a number.
But the Agadez-based Air Info website, citing a security source, said scores of bodies had been buried on Sunday by troops and locals.
A local radio station had said 52 dead bodies had been discovered by authorities on Sunday.
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The 750-km trip from Agadez to the Libyan border takes between two and three days with only very short petrol and toilet stops on the way.
Boudou said searches across a 65-km radius had yielded one dead body "with the identity card of a Nigerian student".
In early June, at least 44 Libya-bound migrants, including women and babies, died of thirst in the Sahara desert after their vehicle broke down in scorching conditions.
In May 2015, the government in Niamey adopted a law banning the trafficking of migrants and refugees with those found guilty facing a prison sentence of between one and 30 years, and fines of up to 30 million CFA francs ($51,000).
Libya has long struggled to control its southern borders with Sudan, Chad and Niger, even before the 2011 uprising that toppled long-time ruler Muammar Gaddafi.
In the chaos that followed, traffickers stepped up their business, with tens of thousands of people each year making the perilous crossing to Italy just some 300km away.
Germany and Italy last month called for a European Union mission to be installed on the border between Libya and Niger to reduce the flow of migrants and refugees.