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.