'Ethnic cleansing' in Kenya - envoy

NAIROBI, Kenya (CNN) -- An American diplomat has described the violence in Kenya's Rift Valley as "clear ethnic cleansing" aimed at chasing out members of the Kikuyu tribe who are loyal to President Mwai Kibaki.

However, U.S. envoy Jendayi Frazer said she did not believe the ethnic clashes that have brought Kenya to its knees following disputed elections last month could be classed as genocide.

The violence she saw this month while visiting the Rift Valley, where Luos people are fighting Kikuyus, "was clear ethnic cleansing," she told reporters at an African Union summit in Addis Ababa on Wednesday.

"The aim originally was not to kill, it was to cleanse, it was to push them out of the region," she said, according to The Associated Press.

Former U.N. Secretary-General Kofi Annan on Tuesday pleaded with Kenya's government to take "extraordinary measures" to protect civilians hours after an opposition lawmaker was killed outside his home.

Hundreds have died in fighting sparked by last month's presidential election, which opponents insist was rigged to ensure Kibaki's re-election.

"Kenya, which has long been a stable and peaceful country, today is in turmoil with innocent men, women and children being hounded and killed," Annan told Kenya's National Assembly before heading into talks with Kibaki and opposition leader Raila Odinga.

Annan's speech came as police and demonstrators clashed in Nairobi and hours after gunmen killed opposition lawmaker Mugabe Were in a car outside his house.

About 100 supporters also gathered in Kisumu, Kenya's third-largest city, in a show of anger over Were's killing, prompting police to fire tear gas and bullets to disperse them, the Kenya Broadcasting Corp. reported. Watch as CNN's Nic Robertson describes unrest in western Kenya's Naivasha »

The western city of Kisumu is a stronghold of the opposition Orange Democratic Movement that has accused the president of rigging the December 27 vote.

Odinga said he suspected "the foul hands of our adversaries" in the shooting death of Were, a parliament member from the Orange Democratic Movement, according to The Associated Press. See dramatic photos following Were's killing »

During his assembly address, Annan called on Kenya's leaders to stop the "downward spiral into chaos that is threatening this beautiful country."

"There is only one Kenya. We all have multiple identifies, but I hope you all see yourself as Kenyans first," Annan said. "[We] must stress our common humanity and uphold respect for human rights and the dignity of others."

The United States is considering imposing sanctions against members of the Kenyan government and opposition figures involved in the recent violence in that country, senior State Department officials told CNN.

Although no decisions have been made, visa and travel bans are among the measures being considered. They do not expect the sanctions to target Kibaki or Odinga, the officials said, but rather those on both sides who are instigating the violence.

U.S. Secretary of State Condoleezza Rice voiced concern Tuesday about Kenya's violence, saying she planned to speak with Annan soon about possible solutions.

Since the election, a spasm of political violence has taken on ethnic overtones as supporters of Kibaki, a member of the Kikuyu tribe, battle with followers of Odinga, from the Luo tribe.

Bloody street battles often have involved machetes. The government says 600 to 650 people have been killed, while the opposition says at least 1,000 have died. The Kenyan Red Cross Society puts the number at 863.

More than 200,000 people have been displaced in the turmoil, according to the Red Cross.

"Right now there is nothing," said tailor Margaret Njambi, who fled with her four children and took refuge in a police station in Kakamega after rioters burned her house and shop. "The house is no more. There is nothing left there for me." E-mail to a friend

CNN's Elise Labott, Saeed Ahmed, Stephanie Halasz and Zain Verjee contributed to this report.

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