Algerian radio said 51 French citizens and 26 from Burkina Faso were among the 116 passengers on the plane which dropped off the radar as it overflew northern Mali.
Apart from seven Algerians, nationals from Canada, Ukraine and Luxembourg were also on board, it said.
An official source in Lebanon said at least 20 of its nationals were also on the flight, including three couples with 10 children.
Its six-member crew were all Spanish, said Spain's airline pilots' union Sepla, while Swiftair confirmed the aircraft had gone missing less than an hour after takeoff from Ouagadougou.
More From This Section
France's Transport Minister Frederic Cuvillier said that top civil aviation officials were holding an emergency meeting and a crisis cell had been set up.
"The plane disappeared at Gao (in Mali), 500 kilometres (300 miles) from the Algerian border. Several nationalities are among the victims," Prime Minister Abdelmalek Sellal was cited as saying by Algerian radio.
Northern Mali was seized by jihadist groups for several months in 2012 and the region has remained unstable despite the Islamists being driven out in a French-led offensive.
Despite international military intervention still under way, the situation remains unstable in northern Mali, which was seized by jihadist groups for several months in 2012.
On July 17, the Bamako government and armed groups from northern Mali launched tough talks in Algiers aimed at securing an elusive peace deal, and with parts of the country still mired in conflict.
"Contact was lost after the change of course."
The carrier, in a statement carried by national news agency APS, said it initiated an "emergency plan" in the search for flight AH5017, which flies the four-hour passenger route four times a week.
One of Algeria's worst air disasters occurred in February this year, when a C-130 military aircraft carrying 78 people crashed in poor weather in the mountainous northeast, killing more than 70 people.