The window of an offshore helicopter came loose as the aircraft flew over the North Sea.

The Leonardo AW189 was on approach to the Forties Charlie platform on Wednesday morning when an external window seal partially detached.

A passenger reportedly held the window in place as the helicopter landed and it remained in place.

No one aboard was harmed and the AW189 underwent a series of safety checks before returning to Aberdeen.

A spokeswoman for Bristow Helicopters said: "Following standard operating procedures, the crew landed safely on the platform with the window remaining in place and the aircraft was shut down for maintenance review.

"Following this review, the aircraft was granted permission to return to Aberdeen International Airport, landing safely just after 5pm without incident.

"Engineering teams are conducting a thorough review to determine maintenance actions needed to return the aircraft to service.

"An alternative aircraft was dispatched to the platform to return the inbound passengers."

It is unclear whether the window was meant to be removable but some can be ejected to allow passengers to escape after an emergency landing.