Authorities say a flight operated by Air Algerie carrying 110 passengers and a crew of six has disappeared from the radar on a flight from Burkina Faso to Algiers.
Air navigation services lost track of the plane 50 minutes after takeoff, the agency said. That means that Flight AH5017 had been missing for hours before the news was made public.
"In keeping with procedures, Air Algerie has launched its emergency plan," the agency quoted the airline as saying.
The flight path of the plane from Ouagadougou, the capital of the west African nation of Burkina Faso, to Algiers was not immediately clear.
Ougadougou is in a nearly straight line south of Algiers, passing over Mali where unrest continues in the north.