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.

Kenya's sex workers are not protected by laws

Following the latest murders, sex workers and human right activists took to the streets to protest against violence and calling for more protection to avoid further killings.

Prostitution is illegal in Kenya, but there is widespread sex tourism along the coast as poverty leads young women and men to become − or being forced to become − sex workers in order to have an income. Most of the young sex workers do not have access to education and are not aware of measures to prevent the spread of sexual transmitted diseases. As a result, HIV and AIDS rates have increased across the country.

According to a report by Open Society Foundation, sex workers in Kenya are affected by stigma, discrimination and lack of legal protection. The report also warned that Kenyan laws against prostitution are in breach of both domestic and international laws.

Felista Abalana, national coordinator of Kenyan Sex Workers Alliance (Keswa), told IBTimes UK that killings of sex workers are common in Kenya. She said: "Sex workers are victims of violence not only in Nakuru, but all over the country. This is because of the laws that exist at county and country level. These laws are punitive for sex workers and make them vulnerable to be treated violently by clients and owners," she continued.

"Sex workers are not protected by the state and people who kill sex workers in Kenya are not prosecuted because police are not keen to investigate a murder of a sex worker," Abalana added. "We advocate for the decriminalisation of sex workers, which is the only way to reduce violence against sex workers."

Keswa also wrote an open letter to Kenyan President Uhuru Kenyatta calling for his intervention to curb violence against sex workers.