A woman in Ndhiwa shouted that she had killed her 14-month son at around 9pm on Saturday night.
Neighbours rushed to her home in Ng’ope village in North Kabuoch ward and found the baby's body and severed head lying separately.
Police are holding the woman at Ndhiwa police station pending investigations.
Konyango assistant chief Gabriel Nyatame said the woman's husband was away when the incident occurred.
Angry residents had tied the woman to a tree within the compound. They wanted to lynch her.
“I reached the home and stopped them from killing the suspect. We reported and the woman was taken to Ndhiwa police station,” Nyatame said.
Ndhiwa police commander Robert Aboki said they will question the woman over the incident before taking her to court.
Aboki said they are going to conduct a mental test at a health facility as part of their investigations.
“The suspect says she beheaded the baby after he refused to breastfeed. But we’re looking beyond this justification,” Aboki said.
The dismembered body was collected and taken to Manyata Kobodo mortuary.