Airlines are cancelling, rerouting and delaying flights to avoid Middle Eastern airspace as Iran vowed to retaliate over the US attack on three nuclear sites.

The Australian government’s Smart Traveller website on Monday updated its travel advice to warn of the possible closure of airspace around transit hubs in the Middle East, impacting flights globally including to Europe, Asia and Africa. “Flights can change or stop at short notice ... borders can close,” it cautioned.