The Nigerian Ministry of Defense says an Air Force Alpha jet on a mission against Islamic extremist insurgents in the country's northeast has gone missing with its two crew members.

A statement Sunday from spokesman Maj. Gen. Chris Olukolade says the German-manufactured jet has been missing since Friday morning when it left its base at Yola, capital of Adamawa state, on a routine mission that was supposed to last 75 minutes.

He said rescue operations are continuing with attempts to contact the two pilots.

The jets have been used in daily bombing raids to dislodge Boko Haram insurgents who have seized a string of towns along Nigeria's border with Cameroon.

Boko Haram has stolen anti-aircraft weapons as well as armored personnel carriers and other weapons in attacks on Nigerian barracks.