Two people are suffering serious injuries after a plane crash in the Northern Territory.
The single-engine aircraft was carrying a pilot and five passengers when it hit terrain on approach to an airstrip and landed upside down at Groote Eylandt in the Gulf of Carpentaria on Friday.
Emergency services treated five people, with at least two taken to hospital in a serious condition.
Engine problems could be to blame.
"During take off, the aircraft experienced engine issues and the pilot attempted to return to Groote Eylandt," Australian Transport Safety Bureau chief commissioner Angus Mitchell said.
"During approach, the aircraft collided with terrain and came to a rest inverted."
The bureau will send a team of investigators to examine the plane wreckage and accident site.
The investigation will consider any recorded data, weather information, witness reports, aircraft operator procedures and maintenance records.
The Anindilyakwa Land Council, representing the local traditional owners, said a number of its employees were involved in the crash.
"All passengers and crew are now receiving medical care," the council posted on social media.
"ALC thoughts and well wishes are with all families impacted."
Groote Eylandt is the largest island in the Gulf, with a population of about 3000 people, and is part of the NT.