Acting on a tip-off, the police, army and CRPF personnel launched a joint operation in Dolamara area under Santipur police station in Bokajan sub-division of the district and came upon a group of seven heavily armed militants.
A fierce encounter followed in which three militants were killed but the remaining four managed to escape.
The security forces recovered three AK-56 rifles and huge quantities of ammunition from the encounter site.
A massive combing operation has been launched in the area to nab the militants who managed to escape, sources added.
