Air-travel disruptions started to ease in the Middle East as a ceasefire deal was reached between Israel and Iran and several Persian Gulf states reopened their airspace.

National carriers in the Gulf resumed flights during the night, with operations restarting at some of the world’s busiest airports. Hubs in Doha and Dubai had closed briefly in preparation for Iran’s missile strike Monday at a US air base in Qatar.

Airports in Bahrain and Kuwait were also operating again on Tuesday, though foreign carriers remained cautious, canceling flights and staying away from a region where millions of passengers pass through every month.

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The pause in the 12-day war between Israel and Iran and the prospects of eased airspace navigation caused shares of European airlines to surge on Tuesday. Deutsche Lufthansa AG, Ryanair Holdings Plc and British Airways owner IAG SA all rose 4 percent or more. Air France-KLM surged 10 percent in Paris, and Turkish Airlines advanced 6.7 percent in Istanbul.

Qatar Airways reinstated flights Tuesday and deployed extra ground staff at Hamad International Airport in Doha to assist the resumption of operations. The carrier operates more than 80 percent of the flights that go through Hamad, according to ch-aviation.com, which compiles industry data.

Emirates, the world’s largest international airline, said it would continue to operate its schedule, using flight paths well distanced from conflict areas after some journeys were rerouted on Monday.

The skies over large swaths of the Middle East have been restricted several times during the past 20 months, making flying through Jordan, Lebanon, Syria, Iraq and Iran difficult.

The closures have forced airlines to cancel flights on profitable routes, pass through countries they usually avoid and take detours that add flight time and extra fuel costs. Dozens of aircraft diverted from Dubai and Doha during the disruptions that lasted several hours.

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The diversions meant some passengers had to fly for longer, stay on the tarmac, or wound up on flights going nowhere. Travelers aboard a Paris-bound Qantas Airways Ltd flight spent more than 15 hours in the air only to find themselves back where they started from in Australia.

Air India Ltd has suspended flights to and from Europe, the east coast of North America and the Middle East, while fellow Indian carrier IndiGo said scores of its services to the Middle East were disrupted. Japan Airlines Co halted services to Doha until June 27. British Airways flights to Doha remained canceled Tuesday, while Dubai services are operating.

Malaysia Airlines, Korean Air Lines Co and ANA Holdings Inc are operating to Dubai and Doha as normal.