Ten students at Maranda Boys High School in Bondo, Siaya County have tested positive for Covid-19 taking the institution's tally to 11.
The first student tested positive for the disease earlier this week, prompting the Ministry of Health to conduct targeted testing among possible contacts in the county.
Siaya Public Health Director Kennedy Oruenjo confirmed that 10 students out of those who were tested were found to have the virus.
The first student who tested positive is at the Bondo Sub-County Hospital isolation unit.
"We have begun contact tracing. We will give more updates as things unfold," said Oruenjo.
County Director of Education Wamocho Khamala said officials had ensured public health protocols to contain the spread of Covid-19 are in place across the county's schools, adding that internal contacting tracing was ongoing at Maranda High School.
Khamala further noted that one pupil from a primary school in Siaya had tested positive for the viral disease, as had two support staff at a secondary school within the town.
He called on parents with children in schools within Siaya County to remain calm, saying the institutions are safe.
Khamala added that Maranda and the two other schools that had reported cases had been fumigated.
"We did tests on all contacts within the primary and secondary schools, and they turned out negative. The pupil and the two support staff have since got better and returned to their various schools," he said.
Siaya County has recorded 22 more cases in the last 24 hours with 44 others in isolation.
Some 42 out of 44 people are under home-based care, while two are at the isolation unit at the Bondo Sub-county hospital.
Out of 22 latest cases, 16 are from Bondo, three from Gem, two from Alego Usonga and one in Rarieda.
The county has recorded 184 cumulative cases since the first Covid-19 case was reported in Kenya in mid-March, with five deaths.
The county government has directed that markets and other targeted public spaces be fumigated to contain the spread of the virus.