The six are Mirat union Awami League Organising Secretary Shaheedul Islam, 46, Polash Khan, 25, 'Polash', 28, 'Kamal', 32, Swapan Islam, 37, and Ratan Khandaker, 33.
Atrai Police Station OC Mobarak Hossain said the law enforcers detained them after finding their involvement in the vandalism of the idols following a dispute with the Hindus at the neighbourhood over control of an irrigation project at Barhakalipur village.
Referring to witnesses' accounts, the OC said the two sides held a meeting next to a Kali Temple in the village on Friday night to settle the dispute, but the meeting ended with a scuffle between the groups.
The locals called police after they saw the idols were broken early in the morning.
"We've detained the six after finding their involvement in the vandalism in the initial investigation," the OC said.