Chadian authorities will charge nine French nationals with abducting children and fraud, and seven Spaniards with being accessories.
The group, nine French aid workers and journalists and seven Spanish flight crew, were detained on Thursday as they prepared to fly 103 children on a charter plane from the eastern Chadian city of Abeche to live with families in Europe.
Earlier, the French President, Nicolas Sarkozy, denounced the French charity workers.
Mr Sarkozy said their actions were illegal and unacceptable.
The charity, Zoe's Ark, insists that it was trying in good faith to take orphans in Darfur abroad for medical treatment.
The UN believes many of the children are from villages in Chad.
Authorities there have detained nine French nationals and the Spanish crew of a chartered plane on suspicion of kidnapping.
