The Inspector General of Police David Kimaiyo said the officers recovered an AK47, 145 rounds of ammunition, five magazines and several IEDs.
Other attackers are said to have escaped with gunshot wounds.
Detectives were on Friday examining the IEDs as investigations commence.
He said the men were part of a gang planning to damage the station that supplies power using special generators.
“Our officers are alert and we have beefed up security in the area,โ said Mr Kimaiyo.
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