June 23 (Reuters) - Commercial airlines around the world

on Monday were weighing how long to suspend Middle East flights

after the U.S. struck Iran.

Singapore Airlines, one of the highest-profile in

Asia, had called the situation "fluid" on Sunday as it cancelled

flights from Singapore to Dubai following a security assessment.

The Middle East route has become more important for flights

between Europe and Asia since Russian and Ukrainian airspace

closed due to war, but flight tracking website FlightRadar24

showed empty space over Iran, Iraq, Syria and Israel.

Air France KLM said on Sunday that it cancelled

flights to and from Dubai and Riyadh on Sunday and Monday.

British Airways, owned by IAG ICAG.L, also cancelled flights to

and from Dubai and Doha for Sunday. It was still reviewing the

situation, it said in a statement on Sunday evening, when asked

about later flights.

Missile and drone barrages in a growing number of conflict

zones represent a high risk to airline traffic, and an

organization that monitors flight risks, Safe Airspace, a

website run by OPSGROUP, warned on Sunday that U.S. attacks on

Iran's nuclear sites could heighten the threat to American

operators in the region.

In the days before the U.S. strikes, American Airlines ( AAL )

suspended flights to Qatar and United Airlines

did the same with flights to Dubai.

Airlines are also concerned about a potential spike in oil

prices following the U.S. attacks, which will increase the cost

of jet fuel.

Israel meanwhile is ramping up flights to help stranded

travellers at home and abroad. 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. Israeli airline El Al on Sunday said it had

received applications to leave the country from about 25,000

people in about a day.