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