ACT police investigate sex worker attacks

Canberra police are hunting a group of men thought to have gang-raped and robbed at least six sex workers.

ACT Policing's Sexual Assault and Child Abuse Team has been investigating reports of violent sexual assaults and robberies since last month under Operation Sparren.

They're aware of six incidents involving the same offenders.

Police say the men, who operate in groups of two or three, make an individual appointment with a female sex worker through an online ad. The man then lets in one or more others.

Women have been aggressively sexually assaulted, sometimes at knifepoint. Some have also been robbed at knifepoint.

Detective Sergeant David Crowe said there may be other victims who have yet to come forward and report sexual assault or robbery incidents.

"Police recognise the emotional hardship and courage involved in coming forward if you are a victim of a sexual assault," he said in a statement.

Two of the men are described as Middle Eastern or Indian in appearance. A third is described as African in appearance.