A CISF constable allegedly shot dead four of his colleagues with his service rifle (5.56 mm INSAS) at the Nabinagar power plant in Aurangabad on Thursday. The accused, Balveer Singh, a resident of Raipur village of Aligarh in Uttar Pradesh, has been handed over to the local police and the CISF has ordered an internal inquiry into the incident. Watch what else is making news: According to sources, Balveer Singh had an argument with two of his colleagues, who reportedly teased him about getting a job on compassionate grounds and not being a direct recruit. Police said at around 12:45 pm, Balveer Singh opened fire, killing head constables Bacha Sharma and Amarnath Mishra on the spot. The other two victims, Assistant Sub-Inspector G S Ram and head constsble Arvind Kumar, succumbed to injuries on the way to hospital. Sources said Balveer Singh had been on quarter guard duty at the Nabinagar Power Generating Company Private Limited (NPGCPL) since 9 am. He had reportedly been under stress for a few days following arguments with two of victims. He, however, had not complained to his seniors. Confirming the incident, Aurangabad Superintendent of Police Satya Prakash said the constable has been arrested. “An inquiry has been ordered and we will soon get to know the outcome of the inquiry,” said CISF Deputy Commandant Manjeet Singh.