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The union government has asked the Chhattisgarh government to submit a report on the alleged encounter.
The fierce gunfight killed 19 people and left six jawans wounded.
Ten of those killed are in the age group of 15 to 28 years and include a 15-year-old girl, says the Left.
Speaking to NDTV, K Vijay Kumar, Director General of the CRPF, defended the operation. "We were fired at, it was a justified reaction... Night operations cannot identify which bullet killed whom," he said. He also said that facts have to be looked into and one should let the probe find out the truth.
The alleged encounter took place in the dense jungles of Dantewada in Chhattisgarh.
Villagers say they were attending a meeting when the security forces closed in and opened fire. What remains unclear is why was the meeting being held in the middle of the night, and who fired at and injured the six jawans? Did the Naxals use villagers as shields as they tried to escape?
Villagers in the area admit that they are often forced by Naxal leaders to attend these meetings which serve as indoctrination camps.
"One or two Naxalites might have been there. The killing of innocent tribals will generate more anger and hatred towards police and security forces," said CPI General Secretary S Sudhakar Reddy.
The CRPF says one of its units was fired at before it reacted. The force has ordered an inquiry.
Local Naxals have condemned the incident and have said that innocent villagers were killed by security forces. They have also declared a bandh on July 5 across the Dandakaranya zone which comprises Chhattisgarh, Jharkhand, Odisha and Andhra Pradesh.
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