An Algerian aviation official says the passenger plane missing over Northern Mali has crashed.
The flight, operated by Air Algerie, was carrying 110 passengers and a crew of six when it disappeared from the radar during a journey from Burkina Faso to Algiers.
Pilots had been told to divert because of bad weather and to avoid other aircraft.
The official Algerian news agency said air navigation services lost track of the Swiftair plane 50 minutes after take-off in the early hours of Thursday.
Swiftair, the private Spanish airline, confirmed 116 people were on board.
The flight path of the plane from Ouagadougou to Algiers was not immediately clear. Ouagadougou is in a nearly straight line south of Algiers, passing over Mali where unrest continues in the north.
Northern Mali fell under control of ethnic Tuareg separatists and then al Qaida-linked Islamic extremists following a military coup in 2012. A French-led intervention last year scattered the extremists, but the Tuaregs have pushed back against the authority of the Bamako-based government.
A senior French official said it was unlikely that fighters in Mali had weaponry that could shoot down a plane.
The official, who spoke on condition of anonymity, said the fighters have shoulder-fired weapons which could not hit an aircraft at cruising altitude.
The MD-83 is part of a series of long-range jets built since the early 1980s by McDonnell Douglas, a US plane maker now owned by Boeing.
French transport minister Frederic Cuvillier said the plane vanished over northern Mali. He spoke from a crisis centre set up in the French foreign ministry.
The list of passengers includes 51 French, 27 Burkina Faso nationals, eight Lebanese, six Algerians, five Canadians, four Germans, two Luxembourg nationals, one Swiss, one Belgium, one Egyptian, one Ukrainian, one Nigerian, one Cameroonian and one Malian, Burkina Faso transport minister Jean Bertin Ouedraogo said.
The plane sent its last message at around 1.30am Irish Time, asking Niger air control to change its route because of heavy rains in the area, Mr Ouedraogo said.
The plane had been missing for hours before the news was made public. It was not known why airline or government officials did not make it public earlier.