Dyfed-Powys Police said the incident happened at around 2:30pm on Saturday, March 7, in a lay-by on the A48 westbound at the Llanddarog junction, just before the turn-off for Nantycaws.
Officers are investigating reports that a man was assaulted by eight men who had parked their Harley Davidson motorcycles in the lay-by.
The victim sustained what police have described as “moderate injuries” in the alleged attack.
His car was also damaged during the incident.
Ammanford and Cross Hands officers are now appealing for witnesses or anyone with information to come forward.
They are particularly keen to hear from anyone who may have private CCTV or dashcam footage from the area around the time of the alleged attack.
In a statement, a spokesperson for Dyfed-Powys Police said: “Local officers are investigating an alleged assault that occurred on the A48 Westbound Llanddarog junction, before Nantycaws turnoff, at around 14:30pm on Saturday 7th March.
“The incident was reported to involve 8 men with parked Harley Davidson bikes in a lay-by, assaulting a man with a car.
“The victim sustained moderate injuries, and damage to their vehicle.”
Police have asked anyone with information that could help the investigation to contact them.
