The gangs disbanded and fled as police responded to panicked calls from business owners and passersby. The group apprehended tried to escape down Soi 3, only to discover it was a dead end.
Dozens of teen boys were arrested after two rival youth gangs got into a stick-wielding melee on Loy Krathong.
Police said the arrested youths hailed from sois Nernplabwan and Khao Noi in Pattaya. They were held until relatives retrieved them.
Investigators said the two gangs were feuding to show their bravado for women on the romantic holiday.