RAIPUR:Maoists on FRiday gunned down at least 11 policemen in an ambush that set off an encounter which left four ultras dead in Chhattisgarh’s Bijapur district. A team of Chhattisgarh Armed Police team was ambushed by the Maoists in Metlaperu village forests under Bhadrakali police station area in the district this evening, Additional Director General (Naxal operation) Ramnivas told PTI over phone. (PTI)