The encounter is still going on, they added.
The exchange of fire is underway between a joint team of security forces and ultras in the interior forests of Chintagufa police station area, Deputy Inspector General of Police (Dantewada range) Sundarraj P told PTI.
"As per the preliminary information, five STF jawans have sustained injuries in the encounter," he said.
The joint team, comprising personnel from STF, District Reserve Guard (DRG) and CoBRA (Commando Battalion for Resolute Action), was carrying out an anti-Naxal operation in Chintagufa area, around 500 km from here, he said.
The team members were cordoning off a forest patch in the southern part of Chintagufa when they came under fire from a group of Naxals, the IPS officer said.
The security forces retaliated, triggering an exchange of fire, he said.
The DIG said on getting information about the gunbattle, reinforcement was rushed to the spot and efforts were on to evacuate the injured jawans.
Further details were awaited, he added.
On April 24, 25 Central Reserve Police Force (CRPF) personnel were killed in a Naxal ambush in Burkapal area under Chintagufa police station of limits ofSukma, the worst Maoist-affected district in the state.