In the heated gunfire confrontation, six gang members were fatally injured while two narrowly escaped with suspected gunshot wounds.
Acting on a tip-off, detectives trailed a KCE 475X Toyota Probox along Nyahururu-Nairobi highway, whose 8 occupants were believed to be on a robbery mission.
On sighting the officers, the said occupants opened fire towards the detectives in a bid to escape.
In self defense, the detectives fired back leaving the six dead, from whom six pistols with several rounds of ammunition were recovered.
A pair of handcuffs and a walkie talkie were also found in their vehicle, which has since been towed pending further police action.
The recovered firearms will be subjected to ballistic examination.