"Maoists also suffered casualties," the statement said, adding that the area had been cordoned off. The injured BSF troopers were evacuated to a hospital.
The skirmish took place around noon in a dense forest near Mahla village in Kanker district when a joint team of BSF's 114th battalion and the District Force was out on a search operation, police said.
The patrolling team had launched the operation from the BSF's Mahla camp, located around 250 from Raipur, Deputy Inspector General (anti-Naxal operations) Sundarraj P told PTI. When the security men were advancing through a forest patch, a group of naxals fired at them, leading to a gun battle, he said. The deceased were identified as BSF's assistant sub- inspector Boro, and constables Ramkrishnan, Someshwar and Ishrar Khan.
Assistant commandant Gopu Ram and inspector Gopal Ram were injured in the exchange of fire, he said. Soon after being alerted, reinforcement was rushed to the spot, he said, adding that a search operation was underway in the area. The bodies and the injured personnel were brought to the BSF's Mahla camp later, he said.
Home Minister Rajnath Singh expressed deep anguish over the death of jawans and prayed for the speedy recovery of those injured.
"Deeply anguished over the loss of @BSF_India personnel during an operation against the Naxals in Kanker. They fought valiantly before laying down their lives for the nation. My deepest condolences to the families of these martyrs and prayers for the speedy recovery of the injured," Singh tweeted.
"I have spoken to DG @BSF_India regarding the encounter in Kanker. He has apprised me of the operation. He will be leaving for Chhattisgarh to help the families of martyred BSF soldiers and also assess the ground situation," he said.
Lok Sabha elections in Chhattisgarh
Voting for Chhattisgarh's 11 parliamentary constituencies will take place across the first three phases of the seven-phase Lok Sabha elections.
The first phase of voting will take place in the Maoist-affected Bastar parliamentary constituency on April 11 while other three Maoist-affected parliamentary constituencies - Rajnandgaon, Mahasamund and Kanker - would go to polls in the second phase on April 18.
Surguja, Rajgarh, Janjgir-Champa, Korba, Bilaspur, Durg and Raipur will vote in the third phase on April 23.
The politics in the state is majorly dominated by the Bharatiya Janata Party and the Congress. A BJP stronghold in last one and half decades, it had, however, seen the Congress turn the tables in the November 2018 Assembly elections to storm back to power.
In 2014 Lok Sabha polls, the BJP won 10 seats with 49.7 per cent vote share while the Congress could only manage to win a single seat and got 39.1 per cent votes.