Six migrant workers surrendered to police after beating rival compatriots on a Koh Larn street.
The Nov. 1 brawl was captured on video, with six minutes of footage posted to social media.
The video showed one group of men in their 30s drive past a rival group on motorbikes and then return with wood bars and other weapons. Words are exchanged and then the armed men bludgeon their foes, continuing to beat them even as they laid on the ground.
Burmese migrants Surask Boontavee, 34, Montree Rungreungpaisit, 34, and Ong Kowin, 39, suffered severe injuries while Cambodian To La sustained minor injuries. They were treated initially at Koh Larn Hospital before being transferred to Banglamung Hospital.
Their attackers were not identified and did not speak to the media. Police did not disclose the motive for the brawl.