A woman is in a critical condition in hospital, after being found unconscious at the side of a road in Co Mayo.
Gardaí are appealing for witnesses who may have information about the incident to contact them.
Emergency services were called to a section of the N5, near Islandeady, shortly after 4am this morning.
They were alerted after a passer-by found a woman on the side of the road, with what are described as "unexplained injuries".
The woman, who is in her late 50s, is being treated at Mayo University Hospital.
The road has been closed to allow for a forensic examination and diversions are in place.
Investigating gardaí have appealed for any witnesses to the incident to contact them.
They are also keen to view any dashcam footage from motorists who may have travelled through Islandeady in the early hours of the morning.
