Three suspects were on Monday night arrested after they were found selling narcotic drugs including heroin in Mwingi town.
John Musya, Paul Mumo and Julius Musya aged between 23-24 were arrested as they hawked heroin concealed in seven sachets.
DCI boss George Kinoti said the suspects sell the illegal drugs to twilight girls, who moonlight in the busy town for bread and butter.
Kinoti said over 10 rolls of bhang were also recovered from the suspects.
The suspects were placed in custody pending arraignment in court for being in possession and trafficking in narcotics.
Last week, a woman believed to be a hospital nurse in Nairobi was arrested and 60 pellets of heroin were recovered from her.
Beatrice Awuor Odhiambo, 42, was produced in JKIA narcotics court and police were given two days to hold her while they investigate.
She was arrested on Tuesday when transational crime detectives stormed her house in Nasra area in Kayole.
Police said the woman was believed to be preparing to ingest the narcotic pellets for transport to an unknown destination.
Police say traffickers now commonly use roads as opposed to airports to carry out their business. Heroin is the most trafficked drug by road from Tanzania and through Uganda.
Heroin is made from the seed pods of the opium poppy plant.
Cases of narcotics trafficking have been declining due to police operations.
Kinoti said law enforcers are increasingly trying to rid the country of narcotics and more resources are being allocated to the war on drugs.