Air Algerie flight AH5017 from Burkina Faso to Algiers, which has disappeared from the radar screens, is said to have changed course to avoid collision with another jet before losing contact.
The flight, which depareted from the capital city of Ouagadougou, lost contact with ground control while it was cruising above Malian airspace and was said to be an hour away from the Algerian border.
"The plane was not far from the Algerian frontier when the crew was asked to make a detour because of poor visibility and to prevent the risk of collision with another aircraft on the Algiers-Bamako route," an Algerian aviation source, who did not wish to be identified, told AFP.
"Contact was lost after the change of course."
The aircraft was chartered from Spanish airline Swiftair. There were 110 passengers of different nationalities and six crew members on board the plane.
The flight was scheduled to land at the destination at about 05:10 local time but has not landed six hours post arrival time.