More than 100 children in Chad are being cared for at a day-care centre in Abeche after an alleged attempt by a charity to smuggle them to France last week.
Those accused of participation in the alleged abduction include 16 Europeans - nine French and seven Spanish - who have been in custody in Abeche since Thursday.
The row erupted when Zoe's Ark charity attempted to fly children they believed were orphans from Sudan's Darfur region to France.
The charity says it was trying to take them abroad for medical treatment. But other aid workers say none of the children was being treated for any serious illnesses or injuries.
Abeche is Chad's second city in the east of the country where more than 200,000 Sudanese refugees now live after fleeing the conflict in neighbouring Darfur.
Since the scandal blew up, officials have been pouring into the centre, keen to show they care for the children.
Chad's President Idriss Deby has promised "severe punishment" for what he has described as a "kidnapping" or "child-trafficking" operation.
The group were charged early on Tuesday morning at Abeche's court. If they are found guilty, they face between five and 20 years in prison with hard labour.
After six days in custody - and still dressed in their uniforms and charity T-shirts - the foreigners looked distraught and extremely dishevelled.