Four students from Syokisinga Mixed Secondary School in Machakos drowned in River Athi on Friday.
One body was retrieved but the search for the others was ongoing at the time of this publication.
Yatta sub-county education director Stephen Kitungu noted: "Three boys and one girl, all form one students from Syokisinga Mixed Secondary School have died in River Athi."
He added: "They had gone for a Geography class (field work) with their teacher when they drowned while swimming."
KUPPET executive secretary, Machakos Musembi Katuku sent his message of condolence to the bereaved families.
"I have learned of the drowning of four form one students of Syokisinga Secondary School with a lot of shock and disbelief," Katuku stated.
"It is unfortunate that we have lost young and tender souls," he added.
Heavy downpour and floods that were witnessed during the month of March in various parts of the country led to deaths and disruption of transport as some roads have been rendered impassable.
In Kitui County, five people died after they were swept away by the Enziu River, in Mwingi East Sub-County.
In Nakuru and Narok counties, flash floods caused by heavy downpour had claimed three lives among the victims was a secondary school student.
