The officers, who were on duty in Ughelli area of the state, were killed on 23 and 26 February with six others missing.
The Nigeria Police Force said it had arrested eight suspects in connection with the murder of its officers on a fact finding mission in Ughelli area of Delta.
The Force Public Relations Officer, Olumuyiwa Adejobi, said this in a statement on Saturday in Abuja.
He said the officers on a fact finding mission were on 23 February, ambushed while others on rescue mission were also ambushed, resulting in the death of six police officers.
Mr Adejobi said the arrest followed intensive investigative efforts of police operatives.
According to him, five suspects were initially arrested shortly after the incident while additional three were apprehended at different locations.
He said the arrest of the additional three followed statements and cooperation of those initially arrested five suspects.
Mr Adejobi said the suspects were currently in police custody, assisting with the ongoing investigation.
He said the Nigeria Police Force was committed to ensuring that all those responsible for the murder and other similar crimes were arrested and brought to justice swiftly and decisively.
The police spokesman said the suspects would soon have their day in court, with credible evidence, once investigations were concluded.
He said the police were deeply saddened by the heinous act of violence against its officers who were diligently performing their duty to protect and serve the community.
“Our thoughts and prayers are with the families of the fallen officers during this difficult time.
“We wish to reiterate that killers of our officers in this extant case and many others, have murdered peace and none of them will go unpunished,” he said.
The officers, who were on duty in Ughelli area of the state, were killed on 23 and 26 February with six others missing.
Premium Times reported how on 14 March, some residents of warring communities ambushed and killed 17 officers and personnel of the 181 Amphibious Battalion of the Nigerian Army on a peace mission to Okuoma community in Bomadi Local Government Area of Delta.
Those killed were the commanding officer, two majors, one captain and 13 soldiers.