More than 121 boys below the age of 11 years got sodomised between January and September in Nairobi.
This is according to a report by the Kenya Health Information system (KHIS), eighty-seven boys between 12 and 17 years were defiled.
Additionally, 1,568 rape cases were recorded among young girls.
"552 girls below the age of 11 were also defiled between January and September," the data said.
The President's Advisor on Women's Rights, Harriette Chiggai, said this rise in defilement cases is worrying.
She also said that the culprits are young men, some police officers and some pastors, who initiate young men into sex cults.
On a Friday visit to Gender-Based Violence Centres and Safe Houses in Nairobi county, she notified perpetrators.
She said they target the young, mentally challenged and elderly, who may be molested in a thicket or at the victim's house.
In collaboration with the Nairobi County Gender-based violence coordinator, Roselyn Mukabana, they vowed to incorporate the police in tracking GBV offenders.