In an official statement on the company website E.N.O.T. Corp. wrote that "the enemies disclosed all information and intention" and that they would continue with similar activities in secrecy from now on.
"Our first mission in the sister country of Serbia was predictable in its end but unexpected in size" the statement says.
The victims were migrants who died from injuries inflicted by firearms, the MUP announced.
Pistol shell casings were found next to the bodies, "which indicates these people have been murdered," the daily Blic said.
Police officers are working to shed light on the case.
A prosecutor has investigated the scene along with the police.
According to media reports, Vladan Markovic was attacked by a swarm of hornets in a field in the village of Zlodol, located between the towns of Bajina Basta and Uzice.
The daily Blic said it learned unofficially that Markovic had left a raspberry orchard and was headed back home in Zlodol when he spotted a piglet on the road, that came from a neighbor's yard.
Serbian Foreign Minister Ivica Dacic has assessed that the pope's visit would benefit Serbia.
"My position as a statesman is that the pope's visit would be in Serbia's interest, especially in the context of not recognizing Kosovo. There will hardly be a pope who has more understanding for us than Pope Francis," Dacic told Blic.