The shooting spree killed two people and wounded five others.
Police say the firearms used by the boy in the incident were blank guns that had been purchased online for 16,000 baht each.
Investigators from Yannawa Police Station asked the Southern Bangkok Criminal Court to issue arrest warrants for three individuals.
They were named as Akkarawich (last name withheld), a resident of Yala province; Suwannahong (last name withheld), also from Yala; and Piyabutr (last name withheld), a resident of Bangkok.
Suwannahong and Akkarawich were apprehended in Yala and are being transported to Bangkok for interrogation, while Piyabutr is also in police custody.
The three suspects face charges of possessing firearms and ammunition without permits and illegal sale of firearms and ammunition.
Local media report that one suspect modified the blank guns, another sold them, and the third withdrew the money earned from their sale from an ATM.