A 27-year-old man has died following a collision involving two scrambler motorcycles at Sprucefield near Lisburn, County Antrim.
Police said he was Ryan Phillips, from the Lisburn area.
The incident happened at a lane near a park and ride facility shortly before 19:00 GMT on Sunday.
An 18-year-old man was taken to hospital with injuries which are not thought to be life-threatening.
Police have appealed for information about the incident.