Superintendent of Police Mayur Patel said in the presence of Palamau Divisional Commissioner J P Lakra, Deputy Commissioner K Srinivasan and himself, a team headed by Civil Surgeon Vijay Kumar conducted the post-mortem which was captured on video.
X-rays of the bodies were also taken, he added.
While four bodies had been identified yesterday, four others were identified as Sakendra Pareiha, Mahendra Pareiha, Niraj Kumar and Santosh Kumar today, the SP said.
Four other bodies now remained to be identified.
The 12 rebels had been gunned down by the police in an encounter at Bakoria village in Palamau district, about 140 km from Ranchi, yesterday.