The incident occurred when the Phakla police station house officer Aslam Sher Ansari and a constable had gone to the village to arrest a dacoity case accused Md Mokhatar hiding in his in-law's place there.
Both the policemen were thrashed by a mob which snatched Ansari's service revolver and mobile phone, Katihar's Superintendent of Police Chhatranil Singh said.
Police officials of Purnea district rescued the two policemen and persuaded the mob to return the SHO's service revolver and mobile phone, he said.
Meanwhile, Mokhtar, wanted in a dacoity case in Phuldobhi village under Phalka police station area last year, managed to escape, the SP said.