An 81-year-old woman was robbed at knifepoint by a group of three youths, which included a seven-year-old boy, while five youths were arrested after a series of robberies in the Darwin CBD, including two service stations, a licensed premise, and at least one member of the public, NT Police said.

Commander Daniel Bacon said in a statement that about 10:30am Monday police received multiple reports of a group of three youths harassing people at the Casuarina Square Shopping Centre.

He said an 81-year-old woman was allegedly robbed by the youths, with one threatening her with a knife before the group ran off with her handbag.

Police said they had identified “a number” of the offenders, recovered the handbag, and a seven-year-old boy was returned to the care of an adult.

Comdr Bacon did not say what happened to the two other offenders.

Police also said that about 12:15pm there were reports to police of aggravated robberies across the Darwin CBD, including two service stations, a licensed premises, and at least one member of the public.

He said police used CCTV to track the offenders to a nearby bus, and officers arrested five youths in possession of cash, knives and various stolen property.

Three 11-year-olds were taken into the care of adults, while a 13- and 14-year-old were later charged with property and weapons offences, and bailed to appear in court on March 11, police said.

Comdr Bacon said police believe that at least one of the offenders was allegedly present during the committing of both the Casuarina and Darwin crimes

“All youths have been referred to Territory Families and it is hoped that the team can work with the youths and their families so we do not see this repeated behaviour,” he said.

Police are asking anyone with information to call them on 131 444, and quote reference 24061084, or report anonymously through Crime Stoppers on 1800 333 000.