Emirates, Air India, All Nippon Airways, and Japan Airlines have all announced they will be canceling flights into the United States on Wednesday over concern about interference from 5G cell phone technology.

Emirates said it will only be flying into New York’s JFK, LAX, and Washington Dulles while canceling flights in the following airports: Boston, Chicago O’Hare, Dallas Fort Worth, George Bush Intercontinental in Houston, Miami, Newark, Orlando, San Francisco, and Seattle.

“We are working closely with aircraft manufacturers and the relevant authorities to alleviate operational concerns, and we hope to resume our US services as soon as possible,” Emirates said in a statement.

Air India announced it would be canceling flights between Delhi Airport and San Francisco, Chicago, and JFK while also canceling a flight from Mumbai to Newark. All Nippon Airways and Japan Airways both said it will still allow flights into the U.S. on Boeing 787 aircraft while canceling some flights using Boeing 777 aircraft, according to CNN.

The cancelations come as aviation experts have expressed concern about the effect 5G cellphone technology could have on some airplane instruments, such as radio altimeters. NBC noted:

The concern is that the airwave spectrum used by the 5G technology could clash with the signals used by radio altimeters, measuring instruments that help pilots determine the distance from the ground to the bottom of an aircraft during low visibility operations.

On Monday, several airline CEOs signed a letter warning that 5G could have “catastrophic” consequences on airplane travel and asked for a two-mile buffer zone around airports:

We are writing with urgency to request that 5G be implemented everywhere in the country except within the approximate 2 miles of airport runways at affected airports as defined by the FAA on January 19, 2022. This will allow 5G to be deployed while avoiding harmful impacts on the aviation industry, traveling public, supply chain, vaccine distribution, our workforce and broader economy.

On Tuesday, AT&T and Verizon both announced that they would delay 5G activation on some towers at certain airports on Wednesday, expressing frustration with the Federal Aviation Administration’s lack of preparation.

“We are frustrated by the FAA’s inability to do what nearly 40 countries have done, which is to safely deploy 5G technology without disrupting aviation services, and we urge it do so in a timely manner,” Megan Ketterer, a spokesperson for AT&T, said.

President Biden praised AT&T for agreeing to temporarily delay the rollout around certain airports.

“My team has been engaging non-stop with the wireless carriers, airlines, and aviation equipment manufacturers to chart a path forward for 5G deployment and aviation to safely co-exist — and, at my direction, they will continue to do so until we close the remaining gap and reach a permanent, workable solution around these key airports,” the president said.