Top officials also told PTI that as per the primary investigation, "Military'' dalam of naxals, which operates in Mainpur area of the state, as well as in the neighbouring Orissa, was involved in the ambush.
Police forces had been dispatched in large numbers to look for the Maoists as well as the missing policeman, constable Holaram Sahu.
Sahu's family told police that he was in contact with them. But he had not contacted the police yet, officials said. They added that as per the available information, he had not been abducted by the naxals.
In the ambush along the Chhattisgarh-Orissa border on Monday, nine policemen, including Additional Superintendent of Police Rajesh Pawar, were killed. Sahu was a part of the police team led by Pawar.
As to what went wrong when Pawar's team became the target of a heavy ambush, officials said that naxals took advantage of the situation when the police vehicle broke down.
ASP Pawar knew the area well and was instrumental in the surrender of many naxals, they said.
Meanwhile, state home minister Nankiram Kanwar here said that police officers had been instructed not to venture into naxal-affected areas with a vehicle. The disregard of the instruction proved costly, he said.