Cabin crew and passengers overpowered a man who allegedly threatened to open one of the plane's doors during the flight.

The man was restrained as he fumbled with the controls of an emergency exit door as the Lufthansa plane flew from Frankfurt to Belgrade, the German airline said.

Serbian authorities arrested the man, a Jordanian with an American passport, when the plane reached Belgrade.

The crew and passengers who subdued him - which included members of a Serbian handball team - kept the man restrained for the rest of the flight.

Passengers told Serbia's public broadcaster RTS that the suspect got up mid-flight, banged on the cockpit door and demanded he be allowed in.

He threatened to bring down the plane and cried out that he wished to join Allah and bring all the passengers with him, according to RTS.