Parts of the airport were closed from around 6am owing to a police incident, the airport said in a tweet issued at around 6.45am. Images shared on social media showed a large number of officers and other emergency services personnel in the airport, as well as a bomb disposal robot in operation and a bomb disposal unit in attendance.

"The airport’s central search area is closed due to an ongoing police incident," said the airport. "Check-in remains open to passengers due to depart. More updates to follow."

Police Scotland told the BBC the terminal building had been closed as a precaution but not evacuated, although images shared on social media showed passengers moving to the airport’s multi-level car park at around 8.45am.

A Scottish Fire and Rescue Service spokesperson told STV News two crews were dispatched to the airport shortly after 6am.

Glasgow airport added at around 9.50am: "The terminal’s check-in and central search areas are closed due to an ongoing incident and passengers have been moved outside the building to our covered car park. We are liaising with Police Scotland on site and will provide a further update when we can."