LONDON (AP) — London's Gatwick Airport remains shut while police and airport officials investigate reports that drones were flying in the area of the airfield.

Passengers traveling Thursday were advised to check the status of their flights before heading to the airport.

Gatwick first closed Wednesday night at around 9 p.m. (2100 GMT) when drones were sighted. It reopened at around 3 a.m. (0300 GMT) Thursday morning but shut down again in 45 minutes when drones were spotted.

Many incoming flights have been diverted to other destinations in Britain and continental Europe. The disruption is having a ripple effect on air travel as cancellations mount.

The drone sighting came near the height of the busy Christmas travel season.

Gatwick is a busy airport 27 miles (43 kilometers) south of central London.