At around 3:20pm this afternoon, a woman was allegedly assaulted close to the Baths at Queens Road in Dun Laoghaire.
The injured woman, who is described as Asian, is believed to be in her 20s.
She was taken, by ambulance, to St. Vincent's Hospital with serious neck and arm injuries.
The area is sealed off pending an examination of by Garda Scenes of Crime Examiners.
Anyone with information or who was in the Queen's Road area of Dun Laoghaire this afternoon between 3pm and 4pm should contact Gardaí.