Gunmen on Thursday killed three mobile policemen near the popular Agor Market, on Igarra-Auchi road in Edo.
Eyewitnesses said another policeman was injured when the gunmen opened fire at a police checkpoint.
Eyewitnesses said the unsuspecting policemen put up a gallant fight to exchange fire with the gunmen.
In the exchange of gunfire, it was gathered that one of the attackers died while another sustained injuries.
The injured gunman was said to have been quickly moved by policemen to an undisclosed hospital for treatment and interrogation.
Six rifles belonging to the attackers believed to have come from Okenne in Kogi State were recovered from their hideouts by vigilante members.
Head of the vigilance group in the area, Ibukun Dogo, said the Divisional Police Officer (DPO) called to tell him if the attack him, making him to quickly mobilise vigilantes to the scene.
Dogo said he and his men saw bodies of the three policemen and they traced the attackers to their hideouts.
But Edo Police Public Relations Officer (PPRO) Chidi Nwabuzor, a Superintendent of Police (SP), said he was yet to get details of the incident.