An Air Algerie jet that went missing over Mali Thursday has probably crashed but there has been no trace of the plane yet, French Foreign Minister Laurent Fabius said.

Fabius said there were 51 French nationals aboard the flight from the Burkina Faso capital Ouagadougou to Algiers, which had more than 110 people on board in all.

"Despite intensive searches, no trace of the plane has been found as we speak," he said.

"The plane has probably crashed. The searches are focussing at this stage on a vast strip of Malian territory around the region of Gao," in the north of the west African nation, he said.