A court in Chad has sentenced six French aid workers to eight years of hard labour for trying to take more than 100 children out of the country.
The French aid workers denied involvement in child-trafficking
The six employees of French charity Zoe's Ark were arrested in October.
The charity said at the time it was evacuating refugee children orphaned by the conflict in Darfur so they could be cared for by families in Europe.
Most of the children were however found to be from Chad, which borders Darfur, and with parents who were still alive.
The case has sparked outrage in the former French colony.
The French government says it will now ask the Chadian government to return its aid workers to France.
Under a 30-year-old agreement between the two nations, offenders can be returned to their native country to serve their sentences.
Diplomatic sources in Chad say a transfer could happen soon, although the authorities there are not obliged to agree and France has no punishment of hard labour.
The verdict was delivered on the fourth day of a trial that started on 21 December.
The court found the French nationals guilty of the "attempted kidnap of children, breaching their civil rights".
Most children were not Darfur war orphans, as Zoe's Ark had claimed
It also found the group guilty of "absconding without payment" of bills accrued in their attempt to fly the children out of eastern Chad town of Abeche.
According to AFP news agency, the head of Zoe's Ark, Eric Breteau, and the Sudanese national, Souleimane Ibrahim Adam, were found guilty of the further charge of using forged documents.
A spokesman for Zoe's Ark, Christophe Letien, told the BBC he was "stunned, sickened and confused by this judgement".
He said the fact the defendants were handed the same sentence for different responsibilities proved "that it was a totally unfair trial".
"The evidence of the defence was not even taken into account. It's absolute rubbish," he said.
A lawyer for one of the aid workers, Olivier Desandre-Navarre, said justice had not been done:
"We could have not pleaded, we could have done nothing. We have the feeling the result would have been the same. They didn't take anything into account. They've condemned everyone, to the same sentence, to the same sanctions. It's an unacceptable decision."
A Chadian and a Sudanese national who were also on trial were each sentenced to four years in prison.
Two other Chadians accused in the child-trafficking case were acquitted.
The French nationals briefly went on hunger strike in December to protest at their treatment.
Earlier this month, Chadian authorities said they had dropped the case against another 12 people initially held with the French aid workers.
The 12 - including French journalists and Spanish flight crew - had already been allowed to leave Chad.
The United Nations children's charity, Unicef, has described the French charity's mission to fly children out of Chad as illegal under international law.
French officials also described Zoe's Ark's actions as "illegal and irresponsible".
Mr Breteau say he and his team genuinely believed they were rescuing orphans from Darfur and have accused their local contacts of duping them.
Some 200,000 people are estimated to have been killed in the conflict in Darfur between local rebel groups and militias backed by the government in Khartoum.
The government's Janjaweed militia is also blamed for forcing some 2m people from their homes, many of whom now live in Chad as refugees.