The six-member team visited Basaguda village in the district and interacted with the villagers and others in a bid to "find out the truth".
While the security agencies say all those killed were Maoists, civil society activists claim they were civilians.
The team demanded that all CRPF and CoBRA personnel who participated in the operation on June 28 must be charged under Section 302 of IPC relating to murder and other relevant provisions of the penal code as well as under the SC, ST (Prevention of Atrocities) Act 1989 and prosecuted.
"All CRPF and CoBRA personnel (who participated) must be charged with sexually molesting women and looting and destroying of property," they said in a release.
The activists said the Central and state governments should stop the ongoing process of "brutally suppress the Maoists" and address the issue politically.