A United Airlines flight was diverted to San Francisco after a passenger made a bomb threat, official says

• A flight from LA to Vancouver made an emergency landing in San Francisco on Monday night.
• The diversion followed a bomb threat made by someone on the flight, an airport official said.

A United Airlines flight from Los Angeles to Vancouver made an emergency landing after an alleged bomb threat was made, airport officials said.

Flight UA1909, which left LAX at 7:13 p.m. on Monday, was due to land in Vancouver about three hours later.

However, about an hour into the journey the plane turned around and headed to San Francisco, tracking data from Flight Radar 24 shows.

San Francisco Airport's duty manager said the diversion was caused by a passenger on the flight making some sort of bomb threat, outlets including ABC7 News reported.

On landing, FBI investigators boarded the plane to speak to passengers and it soon became apparent that the supposed threat was not credible.

One passenger who said they were on the flight posted on X that the threat had been made via AirDrop and it was not clear who was responsible.

United Airlines said in a statement to Insider: "United flight 1909 diverted to San Francisco last night due to a potential security issue on board. The flight landed safely, was met by local law enforcement and is now scheduled to depart this morning at 7:00 a.m. local time."

Online flight data showed the 148 passengers were stuck overnight in San Francisco airport. Their replacement flight is due to land in Vancouver at 9 a.m. PT Tuesday – 11 hours after they were scheduled to land.

Bomb threats are not uncommon on US flights and have added to the rising number of "unruly passenger" incidents recorded this year.

As of November, 1,780 reports of dangerous or threatening behavior on board a flight have been made to the Federal Aviation Administration (FAA).

In March, a United flight was grounded in Vermont after a note, discovered in the plane's bathroom, indicated there was a bomb onboard. Nothing suspicious was found.