NAIROBI, Kenya -- The toll of more than 1,000 dead after Kenya's last election makes Monday's presidential vote the most important in the country's 50-year history.

A slate of new races and a presidential candidate who faces charges at an international court also make it Kenya's most complicated.

Voters on Monday will cast ballots in a host of regional races, many of which could turn contentious and potentially violent. But it's the presidential race that pits multiple tribes against one another, each of which desperately wants to win the country's top political prize.

Kenyans have spent the last five years trying to understand how a nation seen as too educated and economically advanced for civil war spent weeks on the edge of it. Political leaders never convened courts to try those responsible for ordering vicious tribe-on-tribe attacks, so The Hague-based International Criminal Court has indicted four top Kenyans.

One of those is Deputy Prime Minister Uhuru Kenyatta, an ethnic Kikuyu, son of Kenya's first president and one of two leading presidential candidates. The other top candidate is Prime Minster Raila Odinga, a Luo whose father was Jomo Kenyatta's vice-president before he was forced out, the latest rivalry in a long-running rift between Kikuyus and Luos.

Adding to the tensions, a raft of Kenyan polls show Odinga and Kenyatta each have support in the mid-40-per cent range. Kenya has eight presidential candidates, but to win the presidency one must receive more than 50 per cent of the vote, making an Odinga-Kenyatta run-off in April likely, a situation that will increase tribal frictions.

"This is a close election, so there is some nervousness and tension that there may be those who won't accept the results," said John Githongo, a former adviser to President Mwai Kibaki on ethics and governance who resigned and then exposed government corruption.

"I think that fear is a real and understandable one, but I'd like to think that we've learned painfully from history."

Githongo notes that both Odinga and Kenyatta have pledged to concede defeat if the votes don't go their way. Kenya's business and tourism communities want to maintain peace. But Kenya has seen violence surrounding every election since 1992, and there are many reasons violence could revisit this election cycle:

-- A secessionist group on Kenya's coast known as the Mombasa Republican Council is planning attacks during the election, the Kenya National Commission on Human Rights warns.

-- Security officials fear the Somali militant group al-Shabab could try to disrupt voting with deadly attacks.

-- Tensions between the Kikuyus -- Kenyatta's tribe -- and the Luos -- Odinga's tribe -- have been high in Mathare, Nairobi's most dangerous slum.

-- Kenya has seen more than 200 people killed in politically-connected violence in recent months in the Tana River region and in Kenya's north.

-- Police say that more than 530,000 illegal weapons are in civilians hands.

-- Aggressive competition is being seen for new governor and senate positions created in the 2010 constitution.

If Kenyatta wins, he has pledged to attend court sessions at the ICC, meaning Kenya would have an absent president. Kenyatta's running mate, William Ruto, also faces charges related to election violence at the ICC. If Odinga wins and Kenyatta refuses to go to the ICC, Odinga may have to order his arrest, an explosive tribal situation.

Some Kenyans believe the action by the ICC has created conditions in Kenya whereby no powerbrokers will order attacks on other tribes, like they have in the past by taking advantage of high unemployment to pay young men low wages to carry out violence.

"Violence this time is minimal because of the fear, the fear of The Hague," predicted Jacob Aywer, a mason who lives in Nairobi's Mathare slum.

As part of post-2007 reforms, Kenyan voters approved a new constitution in 2010. Voters for the first time this year will be voting for the governors of 47 new political divisions known as counties. Those governorships give more tribes a position in power, but they also create some new contentious races over which violence could break out.

The judiciary underwent reforms, and Githongo said most Kenyans now have more confidence in their country's courts, especially the chief justice of the Supreme Court. A new police inspector general -- one who can't be fired by the president -- is also in place.

Inspector General David Kimaiyo told The Associated Press Thursday that he expects a mostly peaceful vote but he acknowledged some violence may happen. He said he has much work to do to improve the police force's tainted image but he is confident the police are prepared to handle security Monday. He said 99,000 police will guard the polls.

Land ownership has been a longstanding grudge between tribes, with some in Kenya feeling that Kikuyus were favoured in land redistributions following independence from Britain, a major source of conflict in western Kenya between the Kalenjin and Kikuyu communities. A land commission has been formed but has yet to make real progress.

The international community is paying much closer attention to this election than it did to the last one. Donors gave $13 million to help the 2007 vote, but have given more than $100 million this time, including $37 million from the U.S. to support the nation's election commission, to train journalists and to fund civic education programs.

Last weekend many of the presidential candidates -- including Kenyatta and Odinga -- attended a prayer rally in downtown Nairobi where they shook hands, pledged to accept the election results and committed to ensuring no violence would break out from their supporters. The candidates also held two televised debates, the first in Kenya's history.

Kenya suffered two months of terrifying violence in late 2007 and early 2008. Tribes attacked one another with machetes. Police fired live bullets at protesters, and attackers burned down a church filled with refugees, killing 28. More than 600,000 fled their homes in fear.

Sunday's prayer rally and the civil debates were held to give Kenyans hope that mass violence will not return.

"Hatred is a virus, a social virus," said Muthufara Morunganu, a Kikuyu who lives in Mathare. "I think the temperature in Kenya has gone down by 65 per cent."