About 9am police saw the wanted man and a 24-year-old Legana man driving a stolen green Nissan pulsar.

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When police tried to intercept the vehicle, the Legana man who was driving the car dumped it in Evans Street and the pair fled on foot.

Detective Senior Sergeant Joe Riley said the Legana driver was arrested a short time later, but the wanted man entered a car yard and allegedly confronted staff with a knife.

"Once this person got into the car yard he managed to gain access to a vehicle that was parked in a service area," Detective Senior Sergeant Riley said.

"That vehicle had keys in it and whilst he was in the process of getting the vehicle started police attempted to arrest him.

"The male was armed with a knife and a scuffle ensued, but the offender managed to get the vehicle started and then drove off, knocking a police officer to the ground."

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The police officer was not seriously injured and Detective Senior Sergeant Riley said no member of the public was harmed.

"A knife was recovered at the scene where the vehicle drove off and we believe that's the knife he was carrying," Detective Senior Sergeant Riley said.

The wanted man is described as being in his mid-20s, with a fair complexion and stubble on his face. He was wearing a white cap, grey hoodie and black track pants.

Police want anyone with information about the whereabouts of the wanted man or a bright red Mitsubish Outlander SUV (registration D79ZN) to contact them on 131 144 or Crime Stoppers anonymously on 1800 333 000.

"The behaviour of both offenders is really careless and it's dangerous to members of the public," Detective Senior Sergeant Riley said.

"The staff at the car yard did everything right, they didn't approach the offender unnecessarily they didn't put themselves in harms way."

Detective Senior Sergeant Riley said the 24-year-old Legana man remained in police custody on Friday afternoon with charges expected to be laid.