Video posted on social media shows the inside of a plane moments after it lost a window mid-flight.

Passengers can be seen on board the Alaska Airlines aircraft, which was carrying 177 people, using emergency oxygen masks but staying remarkably calm.

The flight was forced to make an emergency landing in the US state of Oregon and the US Federal Aviation Agency said the plane “returned safely… after the crew reported a pressurisation issue”.

Alaska Airlines has since grounded all 65 of its Boeing 737 Max 9 aircraft.