Most of those 103 children who were to fly to Europe from Chad appeared to have at least one parent alive, U.N. agencies said.
A French group calling itself Zoe's Ark was stopped last week from flying the children it described as orphans from Sudan's Darfur to Europe, where the group said it intended to place them with host families. Seventeen Europeans have been detained by Chadian authorities, including six French citizens who were charged with kidnapping. The group says its intentions were purely humanitarian.
The Sudanese government, meanwhile, has summoned the French ambassador to voice objections over the matter, and asked Interpol to help apprehend the head of Zoe's Ark.
Aid workers who interviewed the children at an orphanage in eastern Chad where the children are being cared for said most of the children come from villages on the Chadian-Sudanese border region.
"Ninety-one of the children referred to a family environment made up of at least one adult person whom they consider as a parent," the U.N.'s Children Fund, the U.N. refugee agency and the Red Cross said in a joint statement.
The French Foreign Ministry and others have cast doubt on the claims by the little-known group that the children were orphans from Darfur - the western Sudanese region that has for the last four years been a battleground for rebels, government troops and government-allied militiamen.
The International Committee of the Red Cross and the two U.N. aid agencies said several days of talks with 21 girls and 81 boys aged between one and 10 "suggest that 85 of them come from villages in the border region between Chad and Sudan, in the area of Adre and Tine." Adre and Tine are both in Chad.
Interviews continue, the agencies said, to track their families or close relatives.
ICRC, UNICEF and UNHCR also brought food, clothes and other goods to the children, and said they were working closely with the Chadian authorities.
The agencies said some of the children had been treated for small injuries, but that none appeared to be suffering from serious health conditions.
The Sudanese government summoned the French ambassador on Tuesday, the same day several hundred Sudanese students held a protest sit-in in front of French embassy.
The Khartoum government has demanded the alleged kidnappers and those who helped them be handed over to Sudan for trial. The Sudanese Interior Ministry asked Interpol on Wednesday to help apprehend the head of the aid organization.
On Thursday, a delegation of senior Sudanese officials led by the Minister of Social Affairs Samia Ahmed Mohammed was to travel to Chad to monitor the interrogations there and steps that will be taken protect children from future abductions.
According to its Web site, Zoe's Ark, founded in 2005 by volunteer firefighter Eric Breteau, announced in April it planned on "evacuating orphans from Darfur." The group launched an appeal for host families and funding.
Established French aid and adoption agencies had raised questions about Zoe's Ark could legally organize adoption of children from Darfur, and alerted French judicial authorities, according to French newspaper reports.
The French Foreign Ministry in August warned families to be careful. Still, some 300 families reportedly signed up to adopt or foster children, and many were waiting at a French airport last week for the children when they heard members of the group had been arrested.
Of the 17 people detained in Abeche since last week, six were French citizens charged with kidnapping. If convicted, they face up to 20 years in Chadian prison with hard labor.
Three French journalists traveling with the Zoe's Ark members and an eight-member flight crew including a Belgian pilot were under detention as prosecutors tried to determine whether they should be charged.
In a phone conversation, French President Nicolas Sarkozy asked Chadian President Idriss Deby to free the journalists "as soon as possible, with respect to Chadian legislation," Sarkozy spokesman David Martinon said Wednesday. Sarkozy, who has condemned the group's actions, took a softer tone Wednesday and appealed to Deby to respect the presumption of innocence in the case.
Deby promised Sarkozy he would do "everything in his power" to liberate the French journalists being held, the office of the French president said.