The four ultras, who had rewards on their heads, have been identified as Manglu Madkami, Baman Kawasi, Handa and Podiyami Gangi (woman).
While Madkami had a reward of Rs 2 lakh on his head, the three others had a bounty Rs 1 lakh each on their heads.
The arrested Naxals said that they have surrendered due to their disenchantment with the Maoist's ideology and hope to see development in their native areas, the SP said.
All 28 were given Rs 10,000 each under the state government's Surrender and Rehabilitation Policy. (ANI)