They were apprehended from a forested patch under Koyalibeda police station limits yesterday in a joint operation by BSF and district police.
The ultras were involved in an ambush in Bande region last week which had left two policemen dead, a senior police official said.
Based on specific intelligence inputs, a team of paramilitary force and district police carried out a raid in forests near Parokal and Manhakal villages, about 130 km from here, and made the arrests, he said.
They were identified as Sarita alias Sanoti (26), Rajeshwari (21), Kumari Santo, Jay Singh (25), Raju Upendi (24) and Shaniram (28) - all members of various Naxal wings, the official said.