United Airlines flight to Spain returns to US midair due to security threat

A United Airlines flight bound for Spain from US' Newark Liberty International Airport turned around mid-flight Saturday due to a possible security threat in flight.

The flight departed around 6 pm for Palma de Mallorca, Spain, but landed back at Newark at 9:37 pm, 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." 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.

Passengers had to evacuate as the aircraft was swept by Port Authority police, and passengers were rescreened by TSA and Customs and Border Patrol before reboarding. 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.

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.