A United Airlines flight heading for New Jersey had to return to Las Vegas after a flight attendant reportedly noticed a traveler texting about potentially hijacking the plane.

United Flight 1681 was carrying 150 passengers and six crew members as it traveled from Harry Reid International Airport to Newark Liberty International Airport Saturday night when a flight attendant noticed alarming messages on a passenger’s phone, according to CBS News.

“The flight attendant saw him texting that he was going to hijack the aircraft. They called me, we went into lockdown, and we returned to Vegas,” the flight’s pilot told an air traffic controller, according to audio of the call obtained by CBS.

“United Airlines Flight 1681 returned safely to Harry Reid International Airport in Las Vegas around 11:05 p.m. local time on Saturday, Oct.…