Two teenagers have severe head injuries after being involved in a fight with sticks outside an East Side home in Alice Springs, NT Police said.

Media manager Rob Cross said the fight happened about 1:20am on Wednesday, leaving an 18-year-old man in a serious but stable condition, and a 17-year-old boy in a critical condition, both in Alice Springs Hospital.

He said detectives from the Southern Criminal Investigation Branch are investigating the assaults.

Anyone with information can phone police on 131 444 or report it anonymously via Crime Stoppers on 1800 333 000.