A police officer was assaulted at Riverside Filling Station on Oban Road in Lochgilphead.
The incident, which happened at around around 8pm on Wednesday night, has been described as unprovoked and a suspect was later arrested.
A red Suzuki Swift car was present at the scene.
Police are appealing for witnesses who may have been in the area at the time and anyone who may have dashcam footage.
Roads policing inspector Archie McGuire said: “Our officers are here to protect communities and keep our residents safe and officers should not be subjected to violence during the course of their duties, as happened during this incident ”
“I would encourage anyone who may have witnessed this incident or was in the area at the time and can check their dashcam footage, to please contact Police Scotland on 101 quoting incident number 3116 of 12th May 2021”.
Police officer assaulted in unprovoked incident at Lochgilphead petrol station