"The Cobra personnel were returning to Chintagufa after having safely escorted the the polling party to a nearby polling centre. Following the ambush the rebels opened fire on the forces resulting into an encounter. Three jawans were killed and another three sustained bullet injuries," Bastar inspector general of police Arun D Gautam told Hindustan Times.
In another incident in the adjoining Bijapur district, three troopers were injured in an IED blast triggered by the guerillas.
"The security forces were deployed to offer routine road security ahead of the polls when the incident occurred," the IG said.
Additional forces have been rushed to the region and extensive search operation carried out.
The Maoists have a presence in 16 out of the 27 districts of Chhattisgarh. Sukma and Bijapur are among the seven districts of Bastar zone affected by the violence unleashed by red brigade.
The Election Commission maintained that the security has been tightened in the Maoist strongholds ahead of Lok Sabha polls. The outlawed left-wing extremists had given a poll boycott call.