A man suffered a serious head injury after being attacked as he walked his dog at a golf course.
Emergency services were called to Cochrane Castle Golf Club in Johnstone, Renfrewshire on Sunday at about 5.55pm, and the 49-year-old was taken to Paisley's Royal Alexandra Hospital for treatment.
Police Scotland said their investigations had uncovered he had been involved in an argument with a group of golfers near the 16th green and 17th tee of the course.
Detective Sergeant Jason Buxton, of Paisley CID, said it was "imperative we trace whoever is responsible".
"We believe the area would have been quite busy with golfers and would appeal to anyone who may have witnessed the incident to get in touch," he said.
"If you were in the area at the time, please think back and get in touch with us if you have any information which may be able to assist our investigation."
Police said anyone with information should contact officers on 101, quoting incident 2784 of Sunday May 1.
Elsewhere in Renfrewshire on Sunday, a man was admitted to hospital with a serious head injury after he was assaulted by a gang of thugs in Bishopton.
The gang of four attacked the 34-year-old victim outside a property on Greenock Road at around 9.45pm and left him lying in the street before he was rushed to the Royal Alexandra Hospital. The Daily Record reports that the attackers fled the scene in a car.
The first suspect is described as in his 20s, of slim build, with short dark hair. He was wearing a grey hooded top with white inside the hood, a black gilet, black bottoms and black trainers with a white sole.
The second suspect is described as in his 20s, tall, of slim build, with a shaved head. He was wearing a grey hooded top, grey/khaki jacket, dark jeans, and white trainers.
There is currently no descriptions for the other two men.