The police opened fire when a mob attacked them and snatched away a revolver when they went to arrest two persons at Uladan village in Odisha's Ganjam district on Monday.
The villagers attacked the police team including the inspector-in-charge of Tarsingi police station and two assistant sub-inspectors with knives and sticks injuring four of them, superintendent of police Ashish Kumar Singh said.
The policemen then opened fire in self defence injuring a villager, he said.
The mob thereafter snatched a revolver from the policemen and fired at them injuring an ASI, he said.
The revolver was yet to be recovered, sub divisional police officer, Bhanjanagar R Ch Sethi said.
The villager and ASI were admitted to the MKCG Medical College and Hospital and the others at Bhanjanagar, the SP said.
Ten persons were arrested while some others fled.
The police were deployed in the village where order was restored.