Updated

At least five bodies were found hacked up in a Nairobi shantytown over the weekend, the latest victims of a series of grisly ritual murders that have rocked Kenya.

The mutilated corpses all had similar cuts on their backs, and at least one victim was missing both his hands. Two women had their breasts cut off and the remaining victims, all male, had their genitals removed.

Riots broke out in the notoriously lawless Mukuru kwa Njenga neighborhood Saturday morning, soon after the bodies were discovered. Residents of the sprawling slum marched to a local police station to protest insecurity in the area, where they say murders routinely go unpunished.

Rumors swirled that a suspect, said to be in police custody, had been spotted licking blood from one of the corpses. Rioters demanded the police turn the suspect over to them so that they could mete out vigilante justice.

The killings are part of a wider pattern that has fed public anxiety in Kenya's many urban slums.

In the last year alone, a quasi-religious sect of Kikuyu tribesmen has beheaded dozens of people in ritual murders, swearing blood-oaths to each other in imitation of the brutal Mau Mau insurgency against British colonial rule that swept Kenya in the 1950s.

This well constituted Mungiki sect has decreed codes of conduct for areas under its control, forcing bus drivers to pay protection money and barring women from wearing pants.

The manner of death in the weekend's killings does not match the Mungiki's preferred methods, however. Police ruled out the gang as suspects, igniting further suspicions that a new criminal gang was at work, or that a single killer was still on the loose.

In a scarring incident last August, a man in Naivasha, a town near the capital of Nairobi, admitted to raping two women repeatedly and draining one of so much blood — which he said he drank — that she died. A Pentecostal bishop was arrested after the man told police he had supplied the clergyman with vials of blood.

The bishop was subsequently exonerated — though not before his church was almost razed by a mob.

Days after the mutilations in Mukuru, even basic facts remained unclear. Police sources disagreed on the number of people taken into custody and whether they had been released. Even the number of deaths was disputed. One daily newspaper, the East African Standard, asserted that seven people had been murdered. Another, the Nation, reported there were five fatalities. The area commander of police initially said that three people had been killed.

At the scene of the crime Saturday morning, residents heckled law officers and threw stones, and riot police had to be dispatched to remove the bodies. Among the rioters was Ferdinand Waititu, the member of parliament for the area, who said:

"These police officers are the ones who are causing all the insecurity here, and we will remove all of them." He looked on as the mob demolished a large perimeter wall to a quarry, which residents said was a hiding place for criminals in the area.

Ritual killings have had a long history in Kenya. Government employees themselves were among those frequently accused of mutilation and vampirism during the colonial era, says Luise White, author of Speaking with Vampires, a history of the phenomenon in Africa.

Anthropologists say the number of cases like this rises during times of financial insecurity and political anxiety — and the trend is growing in Nairobi as much of the country is close to famine.

The price of maize, the primary food staple, has more than doubled in one year after rains failed and post-election violence disrupted the planting season early last year.

The Mungiki gang's political wing, the Kenya National Youth Alliance, told a newspaper that youth recruitment was rising in the face of joblessness and soaring food prices. United Nations officials last week estimated the onset of a major famine in the coming months.