Police are treating the death of a man in his 60s near Randalstown, County Antrim, as murder.
He died following what police described as an incident on Caddy Road.
It is believed a number of vehicles were involved in the incident which was reported to police shortly after midnight.
A woman in her 50s was also assaulted and is being treated in hospital. Her injuries are not believed to be life-threatening.
Police have sealed off the Caddy Road near Randalstown
Det Ch Insp Gareth Talbot said: "At this time investigations are at an early stage but I am treating this as murder.
"I appeal to anyone who noticed any suspicious vehicles or activity in the Caddy Road area at around midnight to contact CID at Ballymena Police Station on the non-emergency number 101."