NEW YORK (AP) — The U.S. entry into Israel’s war with Iran has caused travel disruptions to pile up globally.

Following unprecedented bombings ordered by President Donald Trump on three Iranian nuclear and military sites over the weekend, Iran on Monday launched a missile attack on U.S. forces at Qatar’s Al Udeid Air Base. Qatar had closed its airspace just hours earlier, after both the U.S. and U.K. also urged their citizens to shelter in place there.

The region has been on edge following the weekend strikes from the U.S. — and since Israel began the war with a surprise bombardment on Iran, which has responded with its own missile and drone strikes, earlier this month.

As deadly attacks escalated between Israel and Iran, sections of airspace and airports throughout the region have temporarily closed. And airlines cancelled more flights in recent days, with some halting select routes through the middle of the week — particularly in Qatar and the United Arab Emirates, just across the Persian Gulf from Iran.

Singapore Airlines, for example, canceled some flights to and from Dubai starting Sunday and through Wednesday, citing “a security assessment of the geopolitical situation in the Middle East.” And British Airways has similarly suspended flights to and from Doha through Wednesday.

“Safety is always our highest priority,” British Airlines said in a statement confirming its cancellations to The Associated Press, adding that it “will keep the situation under review.”

Air India on Monday announced it was ceasing “all operations to the region as well as to and from the East Coast of North America and Europe” immediately until further notice. The airline, which is still reeling from a plane crash that killed at least 270 people earlier this month, added that India-bound flights from North America were being diverted or rerouted away from closed airspaces.

Air tracking data from FlightAware showed 705 cancellations worldwide as of Monday afternoon. Dubai International Airport topped the list with 75 cancellations in and out of the airport as of around 5 p.m. ET. And Air India had had the highest amount of cancellations among carriers, totaling 38 as of 5 p.m. ET.

Such disruptions have snarled travel, particularly as central hubs in the Middle East often connect flights worldwide — but experts stress that these kind of airspace closures and flight diversions are critical to ensuring safety, especially if future escalation emerges suddenly.

“It is the responsibility of states, countries to ensure that their airspace is safe for passage of aircraft,” Hassan Shahidi, president and CEO of the Flight Safety Foundation. He added that on Monday “the Qataris did the absolutely right thing to close their airspace because of the threat of conflict.”

Beyond Qatari airspace, Flightradar24 reported that UAE airspace was also closed on Monday. After several hours of diversions, flights appeared to be landing and taking off in the country again.

Monday marks the latest “dramatic increase” in this kind of impact, said Ian Petchenik, director of communications at Flightradar24. And while the future is unknown, he added that it’s important to remember airspace closures and flight cancellations reflect that “airlines, air traffic controllers and flight crews are doing their best to keep everybody safe.”

Shahidi adds that it’s important for travelers to monitor government guidance — such as safety notices from the U.S. State Department.

How long the war lasts and what, if any, future escalation comes next could carry more widespread implications. Beyond disrupting global flight networks farther down the road, Shahidi stresses that it’s very difficult for people who may need or want to evacuate countries impacted by the war to do so without access to commercial flights.

At the same time, he adds, it’s critical that state authorities focus on keeping their skies safe — pointing to past tragedies of passenger flights that were shot down by strikes. That includes Malaysia Airlines Flight 17, which was shot down by Russian-backed forces while flying over Ukraine in 2014, killing 298 people.

“We are all praying and urging resolution to this conflict — and especially as it relates to protection of civilian air travel,” Shahidi said. “We do not want to have an MH17, with innocent lives being lost in a missile strike … We do not want to repeat that history.”