Frazer said she did not consider the eruption of ethnic clashes in Kenya a genocide.
The violence she saw during a visit earlier this month to the country's western region, where the fighting has pitted Kalenjin people against Kikuyu, "was clear ethnic cleansing," she told reporters on the sidelines of an African Union summit in Addis Ababa.
"The aim originally was not to kill, it was to cleanse, it was to push them out of the region," she said.
Kenya, once a leader in the region, is following neighbors like Somalia down a path of disintegration, with no solution in sight as slums burn and thousands fleeing in fear alter the nation's ethnic map - perhaps forever
The international community is pressuring the president and his chief rival to share power to end the crisis over disputed presidential elections. Former U.N. Secretary-General Kofi Annan is negotiating, but says it will take a year just to settle on a plan for resolving the deep-rooted problems that caused anger over stolen votes to turn in murderous hate between neighbors of decades.
Tuesday, police in helicopters fired to turn back mobs. Gunmen killed opposition legislator Mugabe Were as a drove up to the gates of his home, and slums where a tense peace had held for days exploded with machete-wielding gangs setting fire to homes and businesses owned by President Mwai Kibaki's Kikuyu people.
Sabat Abdullah, a slum resident, said a gang hefting machetes dragged a Kikuyu doctor from his clinic "and then cut and cut until his head was off."
Political disputes in Kenya often mushroom into ethnic clashes, but never before with the ferocity and on the scale that has left more than 800 people dead in the month since the Dec. 27 elections that the international community and many Kenyans agree had a rigged vote tally.
It was only the second free election in Kenya, which suffered decades under one-party and authoritarian rule.
Kibaki, whose insistence that he is president has incited some of the violence, on Tuesday deplored the fact that some Kenyans "have been incited to hate one another and view each other as enemies."
Some of the violence is an expression of long pent-up anger by the marginalized majority in Nairobi slums, where 65 percent of the capital's residents balance on the edge of survival. Statistics shows Kenyans growing poorer and in greater number each year while corrupt politicians who mouth pious words about alleviating poverty buy ranches in Australia and lakeside villas in Switzerland.
The Rift Valley has seen the worst violence; thousands of people have set homes ablaze, smashed shop windows to loot goods, and set up blazing road blocks where they hunted for members of rival tribes.
A gang of Luos stoned a Kikuyu man, then slashed him with machetes, then threw him to burn to death on their roadblock of flaming tires.
"We didn't waste time, we had to kill him," said Stanley Ochieng, 25.
In villages around Eldoret, another western town, gangs of young Kalenjins on Tuesday slashed to death four Kikuyus and stone another two until they died, witnesses said. When a helicopter tried to land to intervene, the youths set grasslands ablaze.
At the heart of this countryside conflict are decades-old grudges over land. The Rift Valley is the traditional home of the Kalenjin and Masai. British colonizers seized large tracts of land to cultivate fertile farms there. When much of that land was redistributed after independence in 1963, President Jomo Kenyatta flooded it with his Kikuyu people, instead of returning it to the Kalenjin and Masai.
Kikuyus are Kenya's largest ethnic group, about 22 percent of the population of 38 million. Two of the three presidents since independence were Kikuyu and corrupt patronage politics gave them the edge. Government jobs, government contracts, government land all came their way. For example, most public transport is owned by Kikuyus who employ Kikuyu drivers. Their domination of politics and the economy is deeply resented.
Politicians play to those resentments, the ever-strong hunger for land among the rural poor and ethnic divisions, every time Kenya has elections. December's were no exception.
Human rights groups and others charge that the politicians are manipulating people's anger to orchestrate much of the violence.
Odinga and Kibaki blame each other and have traded charges of "ethnic cleansing." Thousands of Kikuyu have fled the Rift Valley - some fear they will never return, hard-liners say they never should.
The U.N. adviser on genocide and mass atrocities, Francis Deng, issued a warning to them Tuesday, saying "political and community leaders may be held accountable for violations of international law committed at their instigation."
Tuesday in the Rift Valley town of Naivasha, overwhelmed police officers responded with tear gas and live bullets and, when that did not work against a mob of 5,000, they flew in on three helicopters and fired into the crowd. A reporter saw two bodies with bullet wounds, but it was unclear whether the men were killed by police on the ground or in the air.
Then the helicopters swooped down, with officers firing, onto a mob of armed Kikuyus pinning down hundreds of Luos outside the Naivasha Country Club. Kikuyus, armed with machetes and clubs inset with nails, had prevented the Luos from escaping for two days.
Police chief Grace Kakai said the helicopter passes helped evacuate the Luos to safety behind the walls of the prison compound. She denied her officer fired into the crowd. "We were trying to scare them, not hurt them," she said.
A week ago the police, who initially denied killing anyone, admitted they had shot and killed more than 80 protesters. Human rights defenders say the number is much higher.
The police force itself risks falling apart along ethnic divides, with some officers threatening to come to blows and even kill each other over what human rights officials charge are shoot-to-kill orders, according to police officers who have spoken on condition of anonymity for fear of losing their jobs.
With the fabric of society so shredded, Annan said Tuesday that people here must learn again how to be Kenyans - not Kikuyus, Luos, Masai or any of the other 39 tribes.
He was speaking at a ceremony opening a "dialogue process" at which Kibaki and Odinga, stony-faced, did not even shake hands.