"All Egyptian carriers shall avoid overflying Tehran (Flight Information Region). No flight plan will be accepted overflying such territory," the notice said, referring to the three-hour period specified.

Egypt's civil aviation ministry later confirmed on Wednesday the notice was intended to reduce flight-safety risks in light of a notification it received from Iranian authorities.

"Military exercises will be conducted over Iranian airspace on Aug. 7 from 11:30 to 14:30 and from 4:30 to 7:30 on Aug. 8 Tehran time," the statement said.