A 20-year-old man has been killed in a head-on collision involving a large truck and a car in southeast Saskatchewan.

The RCMP said Thursday morning the crash happened at 11:25 p.m. the night before near the town of Macoun, on Highway 39 northwest of Estevan.

The victim was the driver and lone occupant of the westbound car. He died at the scene, the RCMP said.

The driver of the eastbound semi-trailer was not injured.

The highway was closed to traffic for about eight hours while accident investigators worked at the scene.

Police have not released the name or home town of the victim.

The cause of the accident isn't known. The accident remains under investigation, the RCMP said.