Three security guards were killed and one injured at a power station in the Damnoen Saduak district of Ratchaburi province on Friday night, allegedly over a pay dispute.
The chief security guard, identified by police as “Boonlert”, has been taken into police custody for questioning.
Police say that the shootings stemmed from a fierce argument between the four guards and their chief over their monthly salaries.
According to an initial report, Boonlert summoned the guards for talks about their pay, but the two sides could not agree on the amount.
In a fit of anger, Boonlert allegedly pulled out his 9mm handgun and fired at the guards, killing three of them and injuring another.
All the victims were taken to the district hospital by the emergency services.