The Middle East was thrown into chaos over the weekend following a war that broke out in Iran and escalated to the wider region with retaliatory attacks, forcing airlines to cancel flights and damaging some of the busiest airports in the world.

As of Monday morning, hundreds of flights had been canceled in and out of the United Arab Emirates, Israel, Bahrain, Qatar, Jordan, and Saudi Arabia, according to flight tracker FlightAware. Dubai International Airport (DXB), one of Travel + Leisure readers’ favorite international airports and recently named the busiest in the world, had to cancel at least 80 percent of incoming and outgoing flights.

Both DXB and Abu Dhabi’s Zayed International Airport (AUH) sustained damage, according to Reuters. DXB said it expected to resume “limited operations” on Monday, but told travelers to first check with their airline.

“Passengers must not travel to the airport and are advised to contact their airline directly for the latest flight updates,” the airport wrote on its website. “We are closely monitoring the situation and will provide further updates as soon as they are available.”

In Qatar, flights to and from Hamad International Airport (DOH) remained suspended. The airport wrote that it was “working closely with government stakeholders and airline partners to look after passengers who have been impacted.”

Airspace also remained closed in Kuwait, Israel, Bahrain, and Iraq, CNN reported, while Jordan partially closed its own airspace from 6 p.m. to 7 a.m.

The closures and flight disruptions have also had a wider impact, affecting flights as far as India and Europe. At least 8 percent of all inbound and outbound flights had been canceled out of Mumbai’s Chhatrapati Shivaji Maharaj International Airport (BOM) as of Monday morning, according to FlightAware. London’s Heathrow Airport (LHR) canceled 4 percent of all incoming and outbound flights.

“The Middle East corridor is India’s largest westbound corridor, and this [disruption] will impact Indigo and Air India heavily,” Sajay Lazar, the CEO of Indian aviation consultancy Avialaz Consultants, told CNBC.

In the United States, domestic airlines, including United Airlines, Delta Air Lines, and American Airlines, issued flight waivers for travel to the Middle East.

For its part, the U.S. Department of State updated travel advisories for Bahrain, Kuwait, and Qatar over the weekend, classifying all three as Level 3, advising Americans to “reconsider travel” there due to “armed conflict.” Israel is also listed under Level 3 “due to terrorism and civil unrest.” At the same time, Iran remains listed at Level 4, the highest advisory, with a “do not travel” warning attached.

Travelers who do plan to head abroad can sign up for the State Department’s free service for real-time travel alerts, the Smart Traveler Enrollment Program (STEP).”