A police officer was killed and two policemen were injured in an encounter with Naxals near Naldih under Kathi Kund police station of Dumka District in Jharkhand.Deputy Inspector General of Police B K Pandey said the officer-in-charge of Jama police station Satanand Singh died on the spot when a bullet hit him in the head during the gunfight. AIR Correspondent reports that the encounter began in the early this morning. Senior police officers have rushed to Dumka from Ranchi.