Cancellations in recent days to usually resilient aviation hubs like Dubai, the world's busiest international airport, and Qatar's Doha by international carriers show how aviation industry concerns about the region have escalated.

The usually busy airspace stretching from Iran and Iraq to the Mediterranean has been largely empty of commercial air traffic for 10 days since Israel began strikes on Iran on June 13, as airlines divert, cancel and delay flights through the region due to airspace closures and safety concerns.

Leading Asian carrier Singapore Airlines, which described the situation as "fluid", moved to cancel flights to Dubai through to Tuesday, having previously cancelled only its Sunday service.

IAG group member Iberia cancelled Sunday's and Monday's Doha flights after making its own assessment, a spokesperson said. It has not made a decision regarding later flights.

Air France KLM cancelled flights to and from Dubai and Riyadh on Sunday and Monday, and Finnair cancelled flights from Doha until at least Tuesday.

Kazakhstan's Air Astana cancelled flights to Dubai on Monday.

However, some international airlines were expecting to resume services.

Flightradar24 departure boards show British Airways, owned by IAG, was set to resume Dubai and Doha flights on Monday after cancelling routes to and from those airports on Sunday.

With Russian and Ukrainian airspace also closed to most airlines due to years of war, the Middle East had become a more important route for flights between Europe and Asia. Amid missile and air strikes during the past 10 days, airlines have routed north via the Caspian Sea or south via Egypt and Saudi Arabia.

Added to increased fuel and crew costs from these long detours and cancellations, carriers also face a potential hike in jet fuel costs as oil prices rise following the US attacks.

Australia-based Flight Centre Travel Group said it is getting a small number of customer requests to route journeys to Europe away from Middle Eastern hubs.

"The most common transfer hubs that we're seeing requested are Singapore, Hong Kong, China, Johannesburg, or even direct between Perth and London," said Graham Turner, CEO of Australia-based Flight Centre Travel Group.

AIRSPACE RISKS

Proliferating conflict zones are an increasing operational burden on airlines, as aerial attacks raise worries about accidental or deliberate shoot-downs of commercial air traffic.

Location spoofing and GPS interference around political hotspots, where ground-based GPS systems broadcast incorrect positions which can send commercial airliners off course, are also a growing issue for commercial aviation.

Flightradar24 told Reuters it had seen a "dramatic increase" in jamming and spoofing in recent days over the Persian Gulf. SkAI, a Swiss company that runs a GPS disruption map, late on Sunday said it had observed more than 150 aircraft spoofed in 24 hours there.

Safe Airspace, a website run by OPSGROUP, a membership-based organization that shares flight risk information, said US attacks on Iran's nuclear sites could heighten the threat to American operators in the region.

This could raise additional airspace risks in Gulf states like Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates, it said.

In the days before the US strikes, American Airlines suspended flights to Qatar, and United Airlines and Air Canada did the same with flights to Dubai. They have yet to resume.

While international airlines are shying away from the region, local carriers in Jordan, Lebanon and Iraq are tentatively resuming some flights after widespread cancellations.

Israel is ramping up flights to help people return home, and leave. The country's Airports Authority says that so-called rescue flights to the country would expand on Monday with 24 a day, although each flight would be limited to 50 passengers.

From Monday, Israeli airlines will start to operate outbound flights, the authority said.

Israeli airline El Al on Sunday said it had received applications to leave the country from about 25,000 people in about a day.