UPDATED: An 18-year-old woman was airlifted to Royal Darwin Hospital on Sunday afternoon after being stabbed in the head with a spear, NT Police said, with the alleged 21-year-old male offender who is known to her arrested after initially going on the run.

Police were informed of the incident in the remote community of Angurugu around 12:05pm Sunday, with police and local health clinic staff attending the scene to find the woman conscious with the spear still embedded in her head.

The woman was airlifted to RDH via Care Flight and is in a serious but stable condition, police said in a Sunday statement.

A 21-year-old man who police were searching for turned himself into police at the Angurugu Police Station on Monday, police said in a statement on Tuesday.

He was charged with recklessly endangering serious harm, aggravated assault and being armed with an offensive weapon and was scheduled to face Darwin Local Court on Wednesday.

The 18-year-old woman is still in hospital receiving treatment for her injuries.

Meanwhile, police are also looking into an aggravated robbery that occurred in Katherine at 4:30am Sunday morning involving a woman being stabbed near the Katherine Showgrounds..

Police reported recieving a call about the stabbing incident involving a 19-year-old woman who was walking through a field when an unknown male approached her, stabbed her in the leg, and stole some money before fleeing the scene.

However, police said the perpetrator later returned the stolen money and stayed with the victim until she was able to flag down a passing motorist. The victim was transported to Katherine Hospital, where she received treatment for non-life-threatening injuries.

Police are continue investigations to locate the alleged robber.

Detectives ask anyone with information, including any relevant CCTV or dash cam footage, to call 131 444 and quote reference number P25193841.

“Anonymous reports can be made through Crime Stoppers on 1800 333 000 or via https://crimestoppersnt.com.au,” police said.