At least two security personnel were also injured in the exchange of fire in Bhaliagada jungle under Mohana police station area, police said.
"We have received information about the death of five Maoists during an exchange of fire in the jungle. The bodies are yet to be recovered as the operation is still on," DIG of Police (Southern Range) R K Sharma said.
The slain ultras belonged to a group headed by Maoist leader Sabyasachi Panda, he said.
Panda, who was recently expelled from the CPI (Maoist), had formed the Odisha Maobadi Party.
Although Panda was present in the camp during the operation jointly conducted by the Special Operation Group and District Voluntary Forces, his whereabouts were not known immediately, the DIG said.
Superintendent of Police (Gajapati) C S Meena said the operation was launched in the jungle after specific information about movement of Maoists.
Meena is coordinating the operation with Superintendent of Police (Ganjam) Ashish Singh.
Berhampur (Odisha): Five Maoists were killed in a fierce encounter with security forces in a forest on the border of Odisha's Ganjam and Gajapati districts on Wednesday.
First Published: Wednesday, November 14, 2012, 14:46