Global travel disruptions will stretch into a fourth day with thousands of flights grounded and airports remaining closed as the conflict widens in the Middle East.

Hundreds of thousands of stranded travellers have scrambled to make new connections since the attacks on Iran by the US and Israel began on Saturday, shutting down most of the airspace over the region.

Etihad said tonight that all flights to and from Abu Dhabi would be suspended until at least 2pm on Tuesday (9pm AEDT).

Emirates said its operations to and from Dubai would be suspended until 3pm on Tuesday (10pm AEDT).

Qatar Airways said it would give an update at 9am on Tuesday (4pm AEDT).

The joint US-Israeli operation on Saturday and the wave of retaliatory strikes by Iran have seen crucial travel routes completely cut off.

The conflict, which has broadened to include strikes on neighbouring nations, has shutdown airports in Dubai, Abu Dhabi and Doha — including Dubai International Airport, one of the busiest in the world. All three were directly hit by strikes.

Cirium, an aviation analytics firm, said it was hard to calculate the number of travellers stranded worldwide.

However, it estimated that at least 90,000 people alone change flights daily in the airports in Dubai, Doha or Abu Dhabi on just three airlines, Emirates, Qatar Airways and Etihad Airways.

Airspace or airports in Israel, Qatar, Syria, Iran, Iraq, Kuwait, Bahrain, Oman and the UAE were closed, according to flight tracking sites and government agencies there.

More than 2800 flights were cancelled on Sunday to and from airports across the Middle East, including those that remained open in Saudi Arabia, Jordan and Egypt, according figures on flight tracking site FlightAware. International airports in London, Mumbai, Delhi, Bangkok, Istanbul, Sri Lanka and Paris each reported dozens of flights cancelled, as well.

- Reported with Associated Press

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