Flights from London to Dubai and Doha have been cancelled after Donald Trump ordered an unprecedented US attack on Iran's nuclear sites.

All of British Airways's flights to Dubai and Doha that were scheduled to depart from Heathrow on Sunday have been cancelled, including return flights, the company said.

The airline made the call after the US struck three nuclear sites in Iran overnight prompting Tehran to launch a retaliatory ballistic missile barrage against Israel.

Israel also announced on Sunday that it had closed its airspace to both inbound and outbound flights in the wake of the US attacks.

The fearful decision comes after a BA flight from London Heathrow to Dubai was diverted to Zurich on Saturday night.