By Rosalind Russell

Nairobi - A wave of grisly child murders in the Kenyan capital has sparked fury among the city's residents, some of whom have tried to take the law into their own hands.

Three people were killed on Tuesday in a riot in a Nairobi slum where tension has been high since the mutilated body of a five-year-old girl was found in a nearby maize field last week.

The naked and disfigured bodies of two other young girls have been found in Nairobi in the past week, and a nine-month-old baby girl is missing from her home.

Kenyan police have warned the public that a serial killer may be at large. No one has been arrested in relation to the killings.

Angry residents, protesting against what they perceive as police inaction, have fought running battles with officers in Nairobi's slum estates.

On Tuesday, a mob killed a man who was walking with his four-year-old granddaughter in Kariobangi estate, accusing him of abducting the child.

The grandfather was just about to board a bus with the girl when he was attacked and lynched by youths - despite efforts by police officers to rescue him, said a police spokesperson, Dola Indidis.

Police then fired into the air and a 20-year-old woman and middle-aged man were killed by stray bullets, he said.

Suspicions that the child murders were related to satanic rituals have heightened fear and anger in Kenya's highly superstitious society, where "mob justice" is commonplace.

"Going by what was found at the scene of the first murder, we can only conclude that it was the work of devil worshippers," a senior police officer told the daily newspaper, The People.

"It was a very grisly, very unique and queer way of doing it and this leaves no doubt there must be a specific reason for it," he said.

In a statement on Wednesday, the Unicef, the United Nation's children's agency, expressed shock at the recent wave of child-killings and kidnappings, and said that between 30 and 50 children had been abducted from around Nairobi in the past year.

"The ongoing abduction and abuse of children in Kenya is one of the most serious violations of human rights," said Nicholas Alipui, Unicef Kenya's director. "It is a situation that requires prompt and extraordinary action." - Reuters