The police said they are looking for a "short" man believed to be the culprit.
Ten female sex workers have been murdered in the city of Nakuru and several of the victims were disfigured and had their private parts removed, local media has reported.
Other reports raised the possibilities that a Mungiki gang, a banned organisation that rejects Western values and religions and fights against modernisation of Kenya, could be be preying on prostitutes.
The police said they are looking for a "short" man believed to be the culprit. Senior commander of police in Nakuru, Hassan Barua, told The Guardian the motive behind the killings is not yet clear.
This is not the first time that sex workers in Kenya have been targeted by a serial killer.
In 2010, Philip Onyancha admitted to having killed up to 19 people, mainly female sex workers, and drinking their blood after, he claimed, a teacher had told him it would bring him fortune. Onyancha is now serving a 12-year jail term in prison.