A motorcyclist has died following a two-vehicle crash at Burwen, near Amlwch.
The A5025 remains closed between Bull Bay and Cemaes following the collision involving a car and a motorbike at just after midday on Saturday afternoon.
Police said the male motorcyclist was pronounced dead at the scene and his next of kin have been informed, along with the coroner for North West Wales.
Anglesey Council said the road is expected to remain closed "for a significant length of time" and drivers are urged to find an alternative route.
A spokesperson added: "Diversion signs are being located along the B5109 from Llanynghenedl towardd Bodedern in the direction of Trefor and on towards Llannerch-y-medd / Amlwch."
An investigation into the crash is underway and detectives are appealing for witnesses to come forward.
Inspector Matt Halstead said: “I share my deepest condolences with the man’s family at this incredibly difficult time."
“I am appealing to anyone who was driving along the A5025 in Burwen shortly before midday todayand who may have witnessed the incident - or who may have relevant dash-cam footage - to come forward as soon as possible."
“Any information could be vital to the investigation.”
Anyone with information should contact North Wales Police on 101 or via the live webchat, quoting incident reference number O101130.


Growing concern for missing hiker
Gwyndod name for SMR station
Bangor's Storiel celebrates 10th anniversary
Monitoring buoy ends wildlife research
New look for Gŵyl Felin