A 22-year-old man has allegedly told police he shot dead a teenage technical college student on Ranong 2 Road in Dusit district on Monday morning because he stabbed one of his gang members.
He also allegedly said they had consumed kratom-laced drinks before attacking the 16-year-old.
Dusit station chief Pol Col Traipop Paetrat said case investigators arrested Akarapol Sirimekanon, 22, and an 18-year-old male identified only as Thanakorn on Tuesday.
They are suspects in the murder of Pongpeera, 16, a student at Dusit Technical College who was wearing his school uniform when slain on Monday morning.
The two suspects allegedly told police there were four of them and they had consumed kratom drinks before picking on the student.
They said the victim was on his way to school, riding pillion on a friend's motorbike. The approached him on their motorcycles.
Mr Akarapol, who works as a deliveryman and formerly went to school in the Thon Buri area, said there was an argument and alleged that Pongpeera had stabbed Thanakorn, who was riding pillion on another motorcycle. So he shot him.
Thanakorn is a former student of a technical college in Charansanitwong area.