Raipur: In a major attack ahead of the Lok Sabha elections, four Border Security Force (BSF) personnel, including an Assistant Sub-Inspector, were killed and two others wounded on Thursday in a gun battle with Maoists in Chhattisgarh.

The troopers were on a routine area domination patrol duty in deep forested Pakhanjur area in Kanker district when they came under attack from the Maoists with improvised explosive devices (IEDs), triggering an exchange of fire, a BSF official said.

Assistant Sub-Inspector Bipul Borah and Constables Seelam Ramkrishna, Isharar Khan and Tumeshwar were killed in the attack that took place around 11.45 a.m. They were part of 114 Battalion of the BSF, the official said.

"Maoists also suffered casualties," a BSF statement said, adding that the area had been cordoned off. The injured BSF troopers were evacuated to a hospital and stated to be recuperating from their injuries.

Union Home Minister Rajnath Singh expressed anguish over the loss of the BSF personnel and spoke with the paramilitary force's chief, Director General Rajni Kant Mishra, over the incident.

In a tweet, Sigh said: "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. 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 slain BSF soldiers and also assess the ground situation."

The attack is a major incident ahead of the Lok Sabha polls as Maoists have given a call for boycott of elections. Earlier, Maoists had dropped pamphlets and also put up banners in the remote areas of Bastar and Kanker constituencies calling for boycott of elections.

A large contingent of paramilitary forces have been deployed in the Maoist-affected constituencies of Bastar and Kanker for search, combing and area domination exercises to ensure smooth polling on April 11 in Bastar constituency and in the second phase on April 18 in Kanker constituency.