United Airlines has canceled some direct flights after the Federal Aviation Administration banned U.S. carriers from Iranian airspace following Iran’s shoot-down of a high-altitude U.S. drone in the area.

Other airlines around the world are following suit and avoiding the area.

The FAA order comes after Iran shot down an unarmed RQ-4 Global Hawk surveillance drone on Thursday that was “operating in the vicinity of civil air routes above the Gulf of Oman,” according to the FAA’s guidance. Iran said it struck down the aircraft over Iranian airspace. The U.S. said the drone was in international airspace over the Strait of Hormuz.

The Strait, which links the Persian Gulf and the Gulf of Oman and sees much of the world’s oil supply pass through it, has been a source of conflict recently, following a series of attacks on oil tankers and escalating tensions over Iran’s nuclear program. The U.S. took steps toward a military strike against Iran in retaliation for the downed drone, but President Donald Trump said he called off the operation Thursday night.

The increased military activity and political tensions in the region pose an “indvertent risk to U.S. civil aviation operations and potential for miscalculation or mis-identification,” the FAA wrote in its guidance. The ban applies to all U.S. carriers and commercial operators.

While the ban from the FAA does not extend to foreign air carriers, airlines around the world have followed the guidance. OPSGROUP, which offers guidance to global air carriers, recommended avoiding Iran’s airspace and the Strait of Hormuz area in a new notice.

“Misidentification of an aircraft is possible,” OPSGROUP wrote. “Civil aircraft were very close to the site of this incident.”

Passenger jets have previously been caught in the crossfire of military standoffs, with deadly results. After flight Malaysian Airlines Flight MH17 was show down over Ukraine in 2014, killing 298 people, all countries have followed advice from the U.S., United Kingdom, France and Germany regarding airspace risk, OPSGROUP said, according to Reuters.

In 1988, the American warship the USS Vincennes shot down Iran Air Flight 655 over the Strait of Hormuz, killing all 290 people on board. Iran eventually sued the U.S., and reached a $131.8 million settlement. Later on, the U.S. awarded USS Vincennes Capt. William C. Rogers the Legion of Merit award, sparking Iran’s anger.

Here’s what to know about the effects of the FAA’s ban.

United Airlines suspends flights

Among U.S. carriers, United Airlines said it suspended its direct flight from Newark to Mumbai because it passes through Iranian airspace. Customers flying to Newark from Mumbai will be accommodated on different flights back to the U.S., a United spokesperson told TIME.

“Given current events in Iran, United has conducted a thorough safety and security review of our India service through Iranian airspace and decided to suspend our service between New York/Newark and India (Mumbai) beginning this evening,” the airline said in a statement.

American Airlines and Delta said they do not fly over Iran.

Global air carriers reroute flights to avoid Iranian airspace

British Airways, Lufthansa, Malaysia Airlines, Singapore Airlines, Qantas, and Dutch carrier KLM said they will reroute their flights to avoid the area, the Associated Press reports.

German airline Lufthansa said it would avoid the Strait of Hormuz and Gulf of Oman, but keep its flights to Tehran on schedule.

Quantas, an Australian carrier, said it would reroute its London flights to bypass the Strait of Hormuz and Gulf of Oman.

Eihad Airways, based in Abu Dhabi, said it had “contingency plans” and would decide “what further action is required” after reviewing the FAA guidance, the AP reports.

Dubai’s Emirates airline said it was rerouting flights away from “areas of possible conflict,” according to the AP. FlyDubai, Emirates’ sister airline, said it adjusted some of its existing flight paths as a precaution.

Write to Mahita Gajanan at mahita.gajanan@time.com.