Police arrested 106 motorcyclists and seized 118 motorcycles illegally modified for road racing, deputy tourist police chief Pol Maj Gen Surachet Hakpal said on Saturday.
Surachet said the arrests were made Friday night by police manning checkpoints on several roads in Samut Prakan to crack down on road racing.
Of the 106 arrested, 27 were under 18 years old, Surachet said.
He said three of the arrested people also tested positive for drug abuse and three others were arrested with a small amount of methamphetamine pills and crystal meth in their possession.