A Serbian passenger was pulled head and shoulders outside a Ryanair-operated Boeing 737 after a cabin window failed shortly after takeoff from Thessaloniki, Greece, forcing the flight to return in an emergency.

The man, aged 61, was seated beside the window when the aircraft suffered a right-engine issue and a rapid loss of cabin pressure while flying toward Memmingen, Germany.

He remained secured by his seat belt as his wife and other passengers grabbed him and pulled him back into the cabin.

The violent decompression triggered oxygen-mask deployment.

Passengers described a loud bang, panic in the cabin and a strong smell before the aircraft turned back.

The injured man was taken to AHEPA University General Hospital in Thessaloniki with neck and shoulder injuries and friction burns; Serbian consular officials said his condition was not life-threatening.

The Boeing 737-800, operated by Malta Air for Ryanair, landed safely in Thessaloniki.

The remaining passengers were later flown to Germany on a replacement aircraft.

What is confirmed is that the aircraft experienced a right-engine issue and cabin depressurization.

Video and photographs show extensive damage around the right engine, and the working theory is that debris from the engine struck the fuselage and dislodged the window.

Investigators have not yet established the exact sequence or cause.

North Macedonia's Aircraft Accident and Incident Investigation Committee is leading the investigation because the incident occurred in its airspace.

The United States National Transportation Safety Board has appointed an accredited representative, with technical support available from the Federal Aviation Administration, Boeing and GE Aerospace.

The aircraft is a 2008 Boeing 737 Next Generation model, not a 737 MAX.

It remains under examination in Thessaloniki as investigators assess the engine damage, the window failure and the aircraft's maintenance history.