Note scribbled on plane toilet forces flight into emergency landing

A threatening message scrawled in a plane toilet has forced the aircraft to make an emergency landing.

The United Airlines Boeing 767-300 flight from Rome to Chicago was diverted on Monday to Shannon Airport in Ireland after the discovery of the note, which reportedly referred to a bomb.

The plane had 214 passengers and crew onboard at the time, and the Irish Times reported police were taking handwriting samples from everybody in an attempt to match it up to the note.

Investigators also conducted a security screening of all hand luggage in the cabin.

The Irish Times reported passengers disembarked about 40 minutes after landing at 1.42pm local time, and were taken to a screening area within the airport.

Passengers were escorted to hotels for the night.

United Airlines said in a statement the landing was due to “a potential security concern”, but declined to comment further.

“After assessing the situation, our crew made the decision to divert to the nearest available airport,” it said.

“Additional security screenings will be performed on all customers and baggage.”

A United Airlines flight was forced to make an emergency landing in Ireland. Source: Getty Images

The airline said on Twitter that the flight was cancelled and would depart for Chicago on Tuesday.

The US government is aware of the incident and is seeking to establish whether there was any violent intent behind the threat, a US government source familiar with the investigation told Reuters.

A second US government source said similar incidents involving threatening notes found on airplanes happened about once a week.

The handwriting on the note was being analysed to see if it matched with any other such notes, which are periodically found on planes, one of the sources said.

It was not clear whether the note was posted in the bathroom prior to take-off or during the flight.