A man is being questioned following an alleged assault outside a supermarket in Holyhead.
Police were called to the car park of the Lidl store at the Penhros Retail Park at around 6.40pm on Wednesday evening.
A 20 year-old local man was arrested on suspicion of three assault and strangulation with intent.
Detectives said they were aware photos of the victims being shared widely on social media.
A North Wales Police spokesperson added: "Please be aware this is a live investigation, and may be considered an offence for anyone to publish anything that may impede any potential future criminal proceedings."
An investigation is continuing and anyone with information or who may have witnessed the assault should contact North Wales Police on 101 or via the live web chat, quoting reference no. 26000238767.
Monitoring buoy ends wildlife research
New look for Gŵyl Felin
Yacht runs aground in Menai Strait
More beach wheelchairs on Anglesey's coast
RNLI crew joins baton relay
