Portland police officers have released images of four male motorcycle riders they would like to speak to in relation to the assaults.

Sergeant Sean Elliott said an incident happened at Lightbody Road about five kilometres east of Nelson around 4pm that Saturday.

He said a middle-aged couple were at the property owned by friends.

When they were leaving the property they were confronted by four dirt bike riders who were trespassing.

"One rider has internationally run his wheel into the wife knocking her to the ground," Sergeant Elliott said.

"The woman has suffered a minor injury to a hand.

"Another rider has then approached the husband and punched him to the face.

"The male victim suffered broken glasses and a swollen left eye."

Sergeant Elliott said the riders were alleged to be confrontational and unnecessarily violent.

"If anyone knows the identity of the men pictured, or witnessed them riding in the area, they are requested to contact Crime Stoppers on 1800 333 000," he said.

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