An unruly passenger caused panic on an international flight by trying to open the back door and have a cigarette at 38,000ft.

Lufthansa flight LH476 from Munich to Vancouver was forced to land in Hamburg at around 2pm on Sunday so the passenger could be removed from the aircraft.

Cabin crew said the man was found in an agitated state at the back of the Airbus A340, and began screaming repeatedly once it had taken off.

Other passengers became nervous when the man appeared to try and prize open the cabin door for a smoke.

A rescue crew including a doctor were quick to the scene when the plane landed and diagnosed the man with a mental health problem, after which he was transferred to a local psychiatric facility.

The flight which usually takes eleven hours was eventually delayed by just over three hours.

Dan Iosch was sitting in first class when the incident happened and told CBC News: “There was a man in the back of the plane screaming and yelling and he apparently tried to force open the back door.

“At the beginning of the flight he was being a little difficult, but they decided to take off.

Iosch watched on as the unnamed man was forcibly escorted from the aircraft by police officers and paramedics.

He added: “The captain was amazing. He had everything in hand and he was calm, but he redirected the plane to Hamburg immediately and we were cleared in straight away.”

Hamburg police confirmed there is to be no formal investigation into the incident.

On May 2 cabin crew had wrestle a woman to the ground as tried to open a door on a Jetstar flight between Sydney and Avalon.