A Malaysia Airlines flight from Melbourne to Kuala Lumpur was forced to turn back after a passenger claimed to have a bomb and tried to force his way into the cockpit.
Flight MH128 left Melbourne on Wednesday night, but turned back only half-an-hour into the journey.
The threatening passenger, who was carrying an unidentified black object, was eventually pinned to the floor by other passengers. The flight landed safely and the man was arrested by airport security.
Passengers' photos show heavily armed security boarding the plane after its early landing.
An audio recording from air traffic control audio has been shared online. In it the pilot is heard, saying the passenger was "claiming to have an explosive device, tried to enter the cockpit, has been overpowered by passengers".
Aussie Rules footballer Andrew Leoncelli was in a seat near the cockpit door when the incident happened, the Sydney Morning Herald reports. He says he saw a man carrying a large black cylindrical object, which looked like a speaker and appeared to have an on/off switch and a charging port.
"He looked like a lunatic," Mr Leoncelli said.
Malaysia's deputy Transport Minister Datuk Seri Ab Aziz Kaprawi told local media the passenger was drunk and was holding a powerbank.