Maoists on Monday night attacked a police outpost in Bihar's Gaya district and killed an assistant sub-inspector and two constables.
The police said a group of suspected Communist Party of India-Maoist rebels stormed the Tankuppa police outpost, about 40 km from the district headquarters, and also looted some firearms and ammunition.
While the ASI has been identified as Upendra Narayan Sinha, the two constables have not been identified.
Another ASI, who was wounded in the attack, has been shifted to Gaya and is in a serious condition.
Gaya Superintendent of Police Amit Jain has rushed to the spot with reinforcements, the sources added.