Algeria’s national airline, Air Algerie, says it has lost contact with one of its planes flying from Burkina Faso.
Contact was lost about 50 minutes after take-off from Ouagadougou, the airline is quoted by Algeria’s state news agency as saying.
The passenger airline was bound for Algiers, it added.
It is unclear how many passengers were aboard flight AH 5017, Reuters news agency reports.
The French military said that two French fighter jets based in West Africa had been sent to try to locate the plane.
France’s civil aviation body said crisis centres had been set up at airports in Paris and Marseille.
The plane is operated by Air Algerie but chartered from Spanish airline Swiftair.
An Air Algerie spokesman quoted by Reuters said the provisional passenger list also included 24 people from Burkina Faso, eight Lebanese, four Algerians, two from Luxembourg, one Belgian, one Swiss, one Nigerian, one Cameroonian, one Ukrainian and one Romanian.
The six crew members are Spanish, according to the Spanish pilots’ union.
Officials in Lebanon, however, said there were at least 10 Lebanese citizens on the flight.
“In keeping with procedures, Air Algerie has launched its emergency plan,” Air Algerie officials, quoted by APS news agency (in French), said.
Later, an Algerian official told Reuters: “I can confirm that it has crashed.”
However, he declined to give any details about what had happened to the aircraft.
Algerian Prime Minister Abdelmalek Sellal reportedly told Algerian radio: “The plane disappeared at Gao (in Mali), 500km (300 miles) from the Algerian border.”
UN troops in Mali say they understand the plane came down between Gao and Tessalit, the BBC’s Alex Duval Smith in the Malian capital Bamako reports.
Brigadier General Koko Essien, who is leading the UN troops, told the BBC that the area leading up to the Algerian border was vast and sparsely populated.
He added that weather in the area had been bad overnight.
Armed groups are also said to be active in the area. However, at the moment the most probable scenario looks like a plane that came down in bad weather, our correspondent adds.
In a statement (in Spanish), Swiftair said that the aircraft was an MD83 and that they were unable to establish contact with it.
An Algerian official had previously told Reuters that the plane was an Airbus A320.
An unnamed Air Algerie company source, speaking to AFP news agency, said: “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.”
“Contact was lost after the change of course.”
Flight AH 5017 flies the Ouagadougou-Algiers route four times a week, AFP reported.
French Transport Minister Frederic Cuvillier told reporters that it was likely there were also many French nationals on board the plane.
In February a military plane in Algeria crashed, killing 77 people on board.
The Hercules C-130 crashed into a mountain in Oum al-Bouaghi province, en route to Constantine, in bad weather conditions. Only one person on board survived.
McDonnell Douglas MD-83
Chris Yates, aviation analyst, said the aircraft was “relatively elderly”
Twin rear-engine, short-medium range airliner
More powerful version of the MD-80 type, based on earlier DC-9
Range: 4,637km (2,881 miles)
Capacity: 172 passengers
First flew: 1984