A Southwest Airlines flight carrying 143 passengers from Los Angeles to Austin, Texas, was diverted and forced to land in Phoenix on Monday evening after a bomb threat was phoned in, officials said.

While the plane was in the air, U.S. F-16 fighter jets were sent to monitor the situation, Michael Kucharek, a spokesman for the joint U.S.-Canadian North American Aerospace Defense Command (NORAD), told Reuters.

Southwest Airlines flight 2675 landed safely in Phoenix Sky Harbor International Airport, where passengers were removed from the plane, an airline spokesperson said.

“Out of an abundance of caution, the captain of Southwest Airlines flight 2675, en route from Los Angeles to Austin, safely landed in Phoenix to look into a possible security threat,” the airline said in a statement.

Phoenix police and FBI bomb technicians searched the plane and found no explosive devices, FBI spokesman Manuel Johnson said. Law enforcement agents also interviewed all of the passengers. A screening of luggage by federal TSA agents was under way late into the evening.

Johnson said an investigation into the caller who initiated the threat was continuing.

The flight was diverted at the request of the Los Angeles Police Department, according to Southwest and the FBI.

Upon landing in Phoenix, the Boeing 737-700 was isolated at the airport away from the main passenger terminal.

Other flights in and out of Sky Harbor airport were arriving and departing as scheduled.

All evacuated passengers were to be taken to Austin "as soon as possible," Southwest Airlines spokeswoman Katie McDonald said.



Reuters contributed to this report.