NEW : Chadian president wants plane , flight crew released . The agencies said they have been interviewing the children individually to determine their backgrounds . Red Cross , UNICEF , NGOs , children that charity wants to fly out of Chad . Most are not from Chad and have disappeared , agencies say . Six members of Noah 's Ark , 11 others under arrest in Chad .
NEW : Chadian president wants plane , flight crew released . Red Cross , UNICEF , NGOs , children that charity wants to fly out of Chad . Most are not from Chad and have disappeared , agencies say . Six members of Noah 's Ark , 11 others under arrest in Chad .