A man wielding a knife has robbed a Christchurch service station, fleeing with a sum of cash.
Police say The Ferry Road service station in Woolston was robbed at 10pm on Sunday.
A man threatened an attendant with the weapon and demanded cash from the till.
The man was tracked by a police dog unit for a short time before they lost the scent.
Police say the man may have used a bike or vehicle to leave the area.