The 28 foreigners arrested in Kapenguria will be arraigned in court and charged with entering the country without valid documents.
The foreigners were travelling from Kakuma Refugee Camp to Nairobi when police apprehended them.
Officers suspect they had either escaped from the camp or entered the country illegally.
The Somali and Sudanese nationals were found outside the designated area of the camp without authority from the Refugee Department.
Kapenguria police boss Wanjuu said they intercepted 23 Somalis, two Sudanese and three juveniles at Tartar junction roadblock along the Lodwar-Kitale highway.
The suspects have been detained at Kapenguria police station and will be taken to court.
The refugees, who had boarded a bus christened Tosha, were arrested following a tip-off.
“We arrested the driver of the bus who said he was innocent. The driver said he did not know the people were refugees who had escaped from the camp. We later released him,” Wanjuu said.
“When leaving the camp they are supposed to have a clearance certificate explaining the reason as to why they have been permitted to leave the camp but they had no document to show their movement. They don’t have any identification document,” Wanjuu said.
He told residents to inform police of any strangers in the area. A crackdown has been launched in all major towns to arrest people who are in the county illegally.