Kenyan President Mwai Kibaki was hoping on Thursday to fend off a fiery opponent in an election that was shaping up to be the closest in the East African nation's history.
Allegations of corruption have been rife, with both Kibaki and challenger Raila Odinga vowing to end the graft that has scared off foreign investment and cost taxpayers millions of dollars.
In Kibera, one of the largest slums in Africa and home to Odinga's main constituency in Nairobi, thousands of people were lining up to vote amid tight security.
There were accusations of voting irregularities, including names that were stricken from the voting rolls. On the eve of the vote, authorities said opposition supporters had stoned three police officers to death in western Kenya, accusing them of being part of a government conspiracy to rig the elections.
Kibaki has denied allegations of vote rigging; 30,000 foreign and national observers are monitoring the vote.
"By and large what I have observed is an orderly process with enthusiastic voters," said Alexander Graf Lambsdorff, chief European Union election monitor in Kenya. "I hope it will stay this way."
Kibaki, 76, unseated the 24-year ruling party in 2002 on an anti-corruption campaign, prompting some Kenyans to start making citizen's arrests of police who demanded bribes. But while he has been credited with helping boost Kenya's economy, his anti-graft campaign has been seen as a failure.
Odinga, a former political prisoner under Kibaki's predecessor Daniel arap Moi, casts himself as a candidate of change. But he, too, has been accused of failing to do enough to help his constituents during 15 years as an MP.
For many observers, however, the very fact that the race is a toss-up is a sign of how far Kenya has come in 15 years of multiparty democracy. An incumbent has never before faced a credible challenge.
When Kibaki ran in 2002, then-President Daniel arap Moi was constitutionally barred from extending his 24 years in power. Moi won in 1992 and 1997 in elections marked by allegations of vote-rigging.
Kenyans also will elect 210 members of parliament and more than 2,000 local council members Thursday.
From NPR reports and The Associated Press