Police are investigating how two small mobs of calves managed to be wandering on State Highway 83 inland from Oamaru.

Four calves were hit by a vehicle and injured while wandering loose on the road near Awamoko yesterday.

Another larger group of cattle were found near Wilson Rd after someone reported the mob to police.

Sergeant Tony Woodbridge, of Oamaru, says an officer found four of the animals had been struck by a vehicle, but no vehicle was at the scene.

Police are keen to know who hit the four calves and drove off, as well as the farmer who owns the stock.