Superintendent of Police Manoj Kumar said on a tip-off that a Maoist operative Bauna Sada was hiding in Kushmahat village, a police team led by SHO Amit Kumar raided the village and arrested him.
However, the villagers started hurling stones at the police team and freed the Maoist, the SP said adding, the police opened fire in its defence.
All six injured policemen, including the SHO, have been admitted to Sadar hospital for treatment, the SP said.
Kumar said the police have launched a combing operation to nab the Maoists and have taken a dozen persons in custody for their alleged involved in the incident.