In a major breakthrough, Chhattisgarh Police has arrested six persons, including self-styled Naxal commander Barsa Lakhma, who were allegedly involved in the gunning down of 76 security personnel in Dantewada in April. <br/><br/>The six were allegedly involved in the killing of 75 CRPF personnel and one state police constable on April six, the biggest attack on security personnel in post-Independence era. <br/><br/>Dantewada Superintendent of Police Amresh Mishra said, the arrested Naxals have told the officials during interrogation that the CRPF personnel had become sitting ducks after they lost the wireless set of the killed Deputy Commandant of the 62nd CRPF Battalion.