A man attacked and killed his two nieces before injuring his own sister in an incident in Bondeni, Upper Matasia in Kajiado North.
Police in Ngong said Saturday they are searching for the suspect behind the murder of the two children aged four and six.
Detectives said he used a sword in the attack.
The suspect is said to be the uncle to the children and a brother to the 19-year-old girl who is his sister.
A neighbour said the children's father had asked her if she had seen his children because the door to his house was locked.
She said she informed him she had not seen them.
The father rushed back to the house and broke the padlock where he found the bodies in a pool of blood.
He said the girl who survived was in pain with injuries.
The neighbors said they had heard screams from the house, but didn't think the children were in distress.
The motive of the attack is yet to be known.
The bodies of the children were taken to Ngong Hospital mortuary while the girl is receiving treatment at Kenyatta National Hospital, police said.
A hunt on the man is ongoing, police said of the Friday incident.
