Officers were called to a disturbance at a car park on Station Road, Callander, Stirling, at around 5.45pm on Sunday, April 25.
A group of motorcyclists were attacked, with three sustaining serious injuries which required medical treatment at Forth Valley Royal Hospital.
The number of attackers is unknown, but all suspects were reportedly wearing dark clothing and some had their faces covered.
They left the scene in vehicles which included a bronze Suzuki car, a black Mitsubishi car, a silver Vauxhall car and a motorcycle.
Detective Sergeant William Harley, of Police Scotland’s Stirling CID, said: “This incident has left three men with serious injuries.“We are asking if anyone was in the area around the time of the incident and may have witnessed this, to come forward and speak to police.
“I would also ask if anyone has any dashcam or CCTV footage that may assist with our investigation, particularly that of Station Road and Main Street Callander, to come forward and speak to officers.”
If you have any information, or if you witnessed the attack, you should contact Police Scotland on 101, quoting incident number 2918 of April 25, 2021.