Egypt instructed all of its airlines to avoid Iranian airspace for three hours in the early morning on Thursday amid tension between Israel and Iran.
The NOTAM, a safety notice provided to pilots on Wednesday, said the instruction would be in effect from 0100 to 0400 GMT. It provided no further details as to why the notice was issued.
"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.
The ministry's press statement followed an unnamed source quoted by the state-affiliated Al Qahera News TV as saying that Iranian authorities had said to avoid flying in Iranian airspace because of "military exercises."