The policemen were reportedly on stop-and-search duty close to a petrol filling station at Rumuigbo when the gunmen struck.
The Guardian gathered that after felling the police officers, the assailants made away with their guns.
Gunmen have targeted and killed about eight police officers this July alone.
Recently, two cops were killed at Eliparawo Junction along Ada-George Road in Port Harcourt, the state capital.
Another happened at a filling station around Agip junction along Ada-George. Two others were killed along Rumuosi/Ozuoba Link Road in Obio-Akpor Local Government Area.
Rivers police command spokesperson, Nnamdi Omoni, confirmed the killing of the three policemen yesterday.
He explained that the Commissioner of Police had ordered thorough investigation to unravel those behind the dastardly act. He promised that the culprits would be arrested and prosecuted for the heinous crime.
In another development, security agents have rescued three chieftains of the Rivers chapter of All Progressives Congress (APC) who were kidnapped by gunmen last weekend.
Enebeli, Austin Enebeli and Afam Onyia were kidnapped on the Elele–Omoku Road.
The party spokesperson, Chris Finebone, said after regaining their freedom on Wednesday, the victims immediately commenced medical treatment.
He lauded security agencies for their timely intervention in various capacities that facilitated the safe release of the three gentlemen.