Seven illegal immigrants, among them five minors, were on Sunday arrested along Isiolo-Moyale highway and taken for questioning by officers of the Anti-Terrorism Police Unit.
Isiolo Sub-county Police Commander Moses Owiti said they were Congolese nationals believed to have escaped from Uganda's Kyangwali refugee camp.
They were heading towards Moyale from Nairobi.
"Our officers, acting on a tip-off, intercepted the Moyale bus and arrested them. Five minors including two aged below five years and three aged above 10 years were in the group," said Mr Owiti.
He identified the adults in the group as Chiza Bayanga, 20, and 29-year-old Furaha Elizabeth.
Mr Owiti said the seven were taken to Isiolo Police Station and will likely be charged with being in the country illegally once police finish the investigation.
Cases of immigrants entering Kenya through the Isiolo-Moyale highway have been on the rise in the past one month.
Close to 30 people from countries including Ethiopia have been arrested and charged.