A United Airlines flight bound for Spain from Newark Liberty International Airport turned around midflight Saturday due to a possible security threat.

The flight departed around 6 p.m. for Palma de Mallorca, Spain, but landed back at Newark at 9:37 p.m., according to the Port Authority of New York and New Jersey. The airline said there were 190 passengers and 12 crew members on board the Boeing 767 aircraft.

According to air traffic control audio, security came to inspect the aircraft after someone named their Bluetooth device a "certain four-letter word."

"They have to inspect the whole aircraft, including the cargo area," the tower can be heard saying, according to audio from LiveATC.net

A passenger posting on social media said crew members repeatedly asked passengers to turn off all Bluetooth devices, but two devices remained on. The flight turned around after communicating with the airline's headquarters in Chicago.

One person posted video on social media showing crew and officers escorting passengers off the plane and onto a bus on the tarmac.

Passengers had to evacuate as the aircraft was swept by Port Authority police, and passengers were re-screened by TSA and Customs and Border Patrol before re-boarding. The airline declined to provide specifics on the cause of the incident.

Passengers boarded a replacement flight with a new crew, which took off early Sunday morning and landed in Palma in the afternoon.

In a statement, the FAA said United Airlines Flight 236 returned to Newark Liberty International Airport on Saturday "after the crew reported a passenger disturbance." According to the FAA, airlines have reported more than 640 unruly passenger incidents so far in 2026.

This was the latest incident with a United Airlines flight this month. On Friday, a domestic flight was diverted because of a security concern with an unruly passenger. Earlier this month, a United flight landing at Newark airport struck a semitrailer truck and a light pole, though no one was injured. The Boeing 767 was traveling at 160 mph at the time of the collision.