UPDATE 4:30 p.m. ET: The plane's wreckage has been found:
UPDATE 11:42 a.m. ET: France's foreign minister said the plane "has probably crashed," though no sign of wreckage has been found.
"Despite an intensive search, at the moment I speak no trace of the aircraft has been found," French Foreign Minister Laurent Fabius told reporters in Paris. "The plane has probably crashed."
UPDATE 9:59 a.m. ET: An Algerian official has confirmed to Reuters that the plane has crashed.
"I can confirm that it has crashed," the Algerian official told Reuters, declining to be identified or give any details about what had happened to the aircraft on its way north.
UPDATE 9:01 a.m. ET: The Associated Press seemed to downplay the possibility that the flight was shot down:
The flight path of the plane from Ouagadougou to Algiers wasn't immediately clear. Ougadougou 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 seems unlikely that fighters in Mali had the kind of weaponry that could shoot down a plane.
The official, not authorized to speak publicly, said on condition of anonymity that they primarily have shoulder-fired weapons - not enough to hit a passenger plane flying at cruising altitude.
Fox News reported that two French fighter jets are in the air and searching for the plane.
Air Algerie said Thursday morning that it lost contact with one of its passenger jets 50 minutes after it departed Ouagadougou, Burkina Faso.
"Air navigation services have lost contact with an Air Algerie plane Thursday flying from Ouagadougou to Algiers, 50 minutes after takeoff," the airline said, cited by national news agency APS, AFP reported.
The missing plane had 110 passengers and six crew members on board, according to Swiftair, the private Spanish airline company that owns the plane.
An emergency plan has been initiated to locate the flight which should have taken about four hours to complete. It was scheduled to arrive just after midnight Eastern Standard Time.
A company source told the AFP that contact was lost with the plane after it was asked to change course while flying over Malian airspace approaching the border with Algeria.
"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," the source told the news agency.
"Contact was lost after the change of course," the source added.
This is a developing news story. Updates will be added.
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