Airlines are continuing to cancel and divert flights in the Middle East after the US and Israel launched strikes against Iran, BBC reported.
Flights in and out of airports in Tel Aviv, Dubai, Doha and other international hubs in the region have been suspended.
The UK Foreign Office is warning British citizens against all but essential travel to Bahrain, Kuwait, Qatar and the United Arab Emirates (UAE). Those already there have been advised to shelter.
Iran has launched attacks on the Gulf states as part its retaliation to US and Israeli strikes which began early on Saturday. Long-haul travel is being affected more widely, with Heathrow urging travellers to check with their airlines, according to BBC.