It was unclear who were buried in the graves but police said they were armed robbers gunned down in a shootout with law enforcement officials and buried by fellow robbers.
There was a gun battle two weeks ago with some robbers at Onueke in Ezza South local government area of the state.
The hoodlums attempted to rob a bank but were unsuccessful, though they dispossessed some residents and site workers of their belongings.
They killed a policeman and shot the bank manager.
Police arrived and engaged them in a gun battle.
Police spokesperson Loveth Odah said three of the robbery suspects were killed in the shootout.
She said, “We have been arresting them and they have been having casualties. They have never come and gone unchallenged. They are no longer unknown gunmen; we have been seeing their faces.
“One was gunned down at Abaomege; two of the ones that went to Ohaukwu a few days ago to attack a patrol vehicle were gunned down.
“Three of the ones that attempted to rob a bank at Onueke, including a woman, were gunned down. Several rounds of ammunition were recovered from them and the Commissioner of Police earned IGP’s commendation as a result of that case.
“We actually bust their hideouts and recovered a lot of arms and ammunition and also discovered three shallow graves in which they buried their members, ‘ explained.