FACTBOX-Facts about Kenyan tribes

Jan 2 (Reuters) - Ethnic rivalries are a reality of life in Kenya, where President Mwai Kibaki's disputed re-election has triggered days of riots and ethnic killings, in which opposition supporters have targeted his Kikuyu tribe, the nation's biggest.

Here are some facts about Kenya's tribal communities:

* Kenya's 36 million people are split into more than 40 different ethnic groups, each with its own strong identity, a variety of cultural traditions, and separate tongues.

* The main groups are -- Kikuyu (22 percent); Luhya (14 percent); Luo (13 percent); Kalenjin (12 percent); Kamba (11 percent), according to government statistics.

* The Maasai, Kenya's best-known tribe and favourite on tourism posters, make up a little over 1 percent of the population. They believe their god gave them all the cattle on earth and were entirely dependent on cattle alone for centuries. Many still live on just milk and fresh blood.

* President Mwai Kibaki is a Kikuyu. His group comes mainly from the agriculturally rich central highlands and wields strong economic power.

* Opposition leader Raila Odinga is a Luo, from western Kenya near Lake Victoria on the border with Uganda. Odinga's Nairobi constituency, Langata, includes one of Africa's largest slums where a large Luo population is fanatically behind him as as are most of the tribe.

* Many Luos feel they have been politically cheated by Kikuyus over Kenya's history. Odinga's father, Jaramogi Oginga Odinga, fell out with founding President Jomo Kenyatta, a Kikuyu, within three years of 1963 independence. The rift worsened when rising Luo politician Tom Mboya was assassinated in 1969, and Luos blamed it on Kenyatta's regime. Odinga says Kibaki cheated him out of a deal to create a prime minister's position in exchange for his Luo votes in the 2002 election.

* Many Kiyuyus feel it was their tribe, along with the closely related Embu and Meru, who shed blood in the Mau Mau rebellion that helped win independence and therefore deserved the spoils of victory, not the Luos. They also place great emphasis on owning property and doing business.

* Former President Daniel arap Moi comes from the Kalenjin group that has produced most of Kenya's famous long-distance runners. The Kalenjin felt threatened by the Luo-Kikuyu alliance at independence, but Moi expertly sidelined both groups during his 24-year term with a divide-and-rule strategy. His allies were also blamed for assassinating rising Luo politician, Robert Ouko, in 1989 in a case that has never officially been solved.

* Kenya is lauded internationally for remaining at peace since independence in 1963, while most of its neighbours in the region experienced war and chaos. But it is often criticised too for failing to tackle tribalism, compared with neighbouring Tanzania, where founding President Julius Nyerere is credited with uniting the whole country against it.

* Ethnic flare-ups are common in Kenya, especially around elections. The worst incidents came in 1992 when some 1,500 died in tribally tinged land clashes in the Rift Valley region. Five years later, another 200 were killed, mainly in fighting in the resort town of Mombasa. (Reporting by Helen Nyambura and Bryson Hull)