UPDATED: Three of the five people involved in a two-vehicle crash on the Arnhem Highway remain in critical condition, with two children also injured, following the incident that occurred about 30km from the Stuart Highway turnoff at noon on Friday, NT Police said.

Police said emergency services attended the scene near the Windows to the Wetlands Visitor Centre on Australia Day, around 1pm. One of the cars involved had only the driver as the occupant while the other car carried four people – reportedly two adults and two passengers under 18.

Three ambulance crews and the Critical Response Unit attended the scene. CareFlight transported the five victims to hospital, three of them in critical condition, a St John NT spokesperson said.

Police said on Monday that the crash involved a family of four in a Toyota Prado and a 22-year-old male in a single-cab Toyota Hilux. All five are still in hospital, including the three still fighting for their lives, including a 53-year-old man, a 42-year-old woman and the 22-year-old male driver of the Hilux

A 10-year-old and 16-year-old also suffered serious injuries in the crash.

Incident Controller Matthew Hollamby said on Monday that the head-on crash occurred during heavy rainfall on Friday.

Police said they believed all people involved were from the Greater Darwin area.

Part of the Arnhem Highway near the tourist spot was closed to inbound and outbound traffic until late Friday evening, with long weekend travellers being stranded in the Adelaide River area, while the NT Major Crash Unit investigated the scene.

Police are urging anyone who saw the crash, or who has dash cam footage from the area around the incident to call 131 444, as investigations continue.