The officers were forced to block part of the busy highway to intercept vehicles driven by the two ferrying the drugs.
Authorities confirmed that the substance was bhang, weighing 298.5Kg, with a street value estimated at Sh8.9 million.
Police intercept and arrest three suspects at Archers Post in Samburu trafficking bhang valued at over Sh5.9m, County Police Commander David Wambua says.
Acting on a tip-off from the public, the officers managed to apprehend two suspects and seized the bhang on Friday night.
Chari Ward MCA Abdillahi Golicha Meja, 27, and his accomplice Nura Abdi Diba, 25, were arrested on the outskirts of Isiolo town.
Kasses says they are yet to get factual information on the said police officers.