Fear has gripped residents of Turi village in Molo sub-county after 17 people tested Covid-19 positive at St Andrew's School, Turi.
Residents said casual employees who work at the institution have continued to mingle with them whenever they leave the school despite the risks.
A source at the school, which admits both local and international pupils, said the patients comprise of learners and teachers.
They have been living at the institution since March when schools were closed due to Covid-19 pandemic.
The source said the patients might have contracted the disease from visitors who came to the school recently in a private chopper.
"It is feared that the victims might have contracted the disease from some visitors who recently landed here in a private chopper," the source said.
It is believed that the group had plans to travel to their homes, outside the country after President Uhuru Kenyatta lifted the travel restrictions.
According to Nakuru County health department, the travel requirement that each person leaving the country tests for Covid-19 helped reveal the infection.
The tests were carried out by a private laboratory ahead of the travel that was scheduled for today.
"A total of 24 samples were picked from the institution and taken for testing where 17 were found positive. All the patients have been isolated in the school," said Dr Gichuki Kariuki, the county heath executive.
He added that the health department has kicked off the contact tracing process to help contain the spread of the virus.
"The patients are asymptomatic and they range from the age of one to 46," he said.