New Delhi: Altogether 161 personnel of the paramilitary forces were killed and 349 others were injured in various encounters with extremists in the last four years, Lok Sabha was informed on Tuesday. Minister of State for Home RPN Singh said of those killed included one SP-rank officer, two DSP-level officers and 108 constables. Among the injured one was an Inspector General of Police- rank officer, one SP-rank officer, five DSP-level officer and 266 constables.