By The Nation
A 16-year-old boy identified only as “Beer” is accused of throwing the grenade at rivals in a crowd gathered in front of a stage for a concert at Wat Wang Ngiew in Moo 4, Dong Charoen district, at 11pm.
Jettrin Phothanan, 15, died at Dong Charoen Hospital of injuries sustained in the blast.
Three other teenagers and Wongduan Suwanwet, 29, were also injured.
Police said the alleged attacker noticed his rivals near the stage and lobbed the grenade at them. He was arrested soon after.
The nature of the rivalry was not immediately clear.