Great Southern Rail, which operates the train, said the derailment occurred about 3.15pm as the train was travelling at low speed into the Katherine terminal.

There have been no reports of injuries to passengers or crew from the derailment which affected two non-passenger carriages.

Passengers were about four hours into the 47-hour journey from Darwin to Adelaide when the derailment occurred.

In a statement on Wednesday night, Great Southern Rail said it was working to ensure the comfort and safety of its passengers while trying to get the train back on track.

The train operator said it anticipated the train would resume its journey about 3.30am.

A spokesman for the Australian Transport Safety Bureau said the authority would investigate the cause of the accident.

Great Southern Rail said passengers were likely to arrive in Alice Springs about 6pm on Thursday evening and it would provide a revised timetable as soon as possible.

Ghan passengers were also stranded in Alice Springs in June when another train derailed near Tennant Creek, blocking the tracks.

The wheels had come off the carriage of a freight train carrying manganese from a Bootu Creek mine to Darwin.