According to sources, nearly 50 armed Maoists raided Chirogora village late on Sunday night and dragged out the three activists from their houses and shot them dead.
The deceased were identified as Leru Majhi, Dasrath Majhi, and Choto Majhi.
Maoist posters claiming responsibility for the killings were found at the site, stating that all the Forward Bloc leaders were corrupt and were leading an anti-Maoist movement in the region.
Maoists are active in West Midnapore, Purulia and Bankura district of the state.
Leftist leaders discuss strategy