At least 22 illegal immigrants were arrested in Shabaa, Samburu West constituency, on Sunday.
The lot, among them a three-month-old baby, is believed to have travelled from Eritrea.
Maralal police boss Abagaro Guyo said members of the public alerted them of a suspicious truck parked in a bush.
"Members of the public who spotted the vehicle parked in a bush at Shabaa alerted Nyumba Kumi members who then alerted the authorities."
Maralal Nyumba Kumi chairman Solomon Wanyeki said: "I think the driver got lost as he evaded roadblocks along the Isiolo Marsabit highway and ended up in Maralal.
"The immigrants looked dehydrated and hungry," he said. He thanked the residents for the information.