An irate dog walker wrestled a fellow pet owner to the ground and then beat him with a plastic ball thrower after a dispute turned violent.
The 49-year-old was attacked by another man whose dog had attacked his pet as they walked in a park in Edinburgh.
During the dispute, the suspect grappled the man to the ground and began hitting him with the plastic dog ball thrower, Police Scotland said.
The victim suffered bruising and swelling to his knuckles, but was not seriously injured after the attack at the Bruntsfield Links at around 10.45 am on Wednesday.
Sergeant Andy Wilson said: "The Meadows is often very busy and this incident may have attracted the attention of anyone who was within the park at the time.
"I would ask any members of the public who witnessed the assault, or can help us identify the suspect, to contact police immediately."
The suspect is white, 5ft 10in, with a medium build, short grey hair and a grey beard.
He was wearing a dark blue jacket, jeans and trainers, and was walking a black labrador.
Anyone with information can contact police on 101 or the Crimestoppers charity on 0800 555 111.