NAIROBI, Kenya - A notorious criminal gang exchanged gunfire with police and put up blazing roadblocks Monday, threatening to spread violence nationwide unless authorities free their leader in an unsettling new danger for Kenya's bloody postelection crisis.
The upheaval started before dawn and killed at least four people as members of the outlawed Mungiki gang protested the death of their imprisoned leader's wife, who authorities said was found beheaded last week. They burned buildings and derailed a train in the capital.
"This is lawlessness and sheer madness," Joseph Kanyiri, a district commissioner in Nairobi, told The Associated Press.
He said the fighting was gang-related and not connected to the flawed Dec. 27 presidential election that set off weeks of bloodshed among rival factions and tribes, tarnishing Kenya's reputation for stability in an African region that includes war-ravaged Somalia and Sudan.
The outbreak comes at a precarious time for Kenya, which just got a power-sharing government that was formed under international pressure in hopes of ending fighting that killed more than 1,000 people after the disputed election.
President Mwai Kibaki named opposition leader Raila Odinga as prime minister Sunday. It is the first time Kenya will have both a president and prime minister, but the two men have long had a frosty relationship and there are worries over whether the coalition can hold together.
Members of the Mungiki, a quasi-religious sect linked to a string of beheadings, took to the streets Monday in several cities, including Nairobi's slums and the western town of Naivasha — areas that in January and February saw some of the worst postelection violence.
Gang members traded gunshots with police just feet from makeshift tent camps housing some of the 300,000 Kenyans who fled the election fighting.
In Nairobi's Dandora slum — a hotbed of Mungiki activity that is infamous for a sprawling, environmentally disastrous waste dump — 13-year-old Dorian Opio peeked out the gates of her primary school as riot police fired bullets and tear gas shells down alleys. Black smoke billowed from a flaming police station next door.
"I don't know if I should walk home," Opio said, fiddling with the strap on her backpack. "I think maybe I should go. All the other students left, but I don't know how I'll get there."
Elsewhere in the slum, Mungiki supporters caused part of a locomotive and several train cars to run off the rails and turn over.
Gang members, who didn't want to be quoted by name for fear of government reprisals, said two people were killed in Dandora. Two people were shot dead in Central province, regional police chief Philip Ndwiga said.
The protesters demanded the release of their leader, Maina Njenga, from prison, and accused police of being behind the death of Njenga's wife and the gang's acting leader last week.
"We will not stop demonstrating," Joe Waiganjo of the Kenya National Youth Alliance, the political wing of the Mungiki, told AP. He said the group planned more protests across the country in coming days.
A spokesman for the national police, Eric Kiraithe, denied any police involvement in the killings.
"That is totally false accusations. Why do the police want to kill this woman?" he asked. "If we are interested in the wife of the criminal, we would have taken her to court."
Mungiki emerged in the 1990s, inspired by the 1950s Mau Mau rebellion against British colonial rule, and has been linked to extortion, murder and political violence. The group is believed to have thousands of adherents, all drawn from the Kikuyu, Kenya's largest tribe and the dominant force in politics and business.
Several burned-out, smoldering cars blocked roads and about a dozen riot policemen with shields and masks guarded a main traffic circle near Nairobi's Mathare slum. Streets were littered with broken glass and the blackened shells of minibuses and cars.
"We are not safe," said 24-year-old Joyce Nyambura, who works at a photo studio in Nairobi's city center but chose not to brave the gunfire to get into town. "We don't know where these Mungiki are, but they seem to be scattered everywhere."
About 25 miles outside Nairobi, around 200 Mungiki members with machetes and sticks blocked a road.
Police and gang members fought running battles in the center of Naivasha, about 60 miles northwest of the capital. In the western town of Eldoret, senior police officer Muinde Kioko said two Mungiki supporters were badly beaten by members of the public and 16 had been arrested.