Five boys aged between 13 and 16 allegedly threw stones at passing buses in Kontum Province early Monday after a bout of heavy drinking, according to police.
The police said Thursday that the boys had hit at least six buses. Several bus drivers reported broken windshields, but no one was hurt.
The authorities have yet to decide how the boys, considered minors under Vietnamese laws, would be punished..
On Tuesday, police in Binh Phuoc Province in southern Vietnam also arrested two men for throwing stones at buses early the same day. The duo claimed they did so under the influence of alcohol.
Stone throwing has been a scary experience to passengers traveling across central Vietnam and provinces to the east of Ho Chi Minh City.
The vandals, most of them young people, used to target trains, but have turned to buses in recent years after operators installed iron nets to protect train windows.
A 2-year-old passenger was injured last month in one such incident in Binh Thuan Province.
A court in central Vietnam in early May 2014 sentenced a 17-year-old boy to four years in jail for throwing stones at two buses running on a national highway, which caused a passenger to lose his left eye last year.
The man told the court that he had thrown stones at passing vehicles “just for fun.”