Jordan, Lebanon and Iraq have shut their airspace in response to Iranian drone attack on Israel.
Iran and Israel have also closed theirs to all but military aircraft.
Iran has launched dozens of drones and missiles at Israel in a retaliatory attack.
Israel has said the attack could take some hours to arrive, while Prime Minister Benjamin Netanyahu said the country is “ready for any scenario.”
Iran’s Defense Minister Mohammad Reza Ashtiani has warned that Tehran will firmly respond to any country that “opens its airspace or territory for attacks on Iran by Israel,” Iran’s semi-official Mehr news agency reports.
Iran had warned that Israel would be “punished” for a strike on its consulate in Syria on 1 April.
Seven Revolutionary Guards, including two generals, and six Syrians were killed in the Damascus attack.