Thousands of Kenyans enraged over the slow return of results in the country's closest presidential election waved machetes and looted shops Saturday as President Mwai Kibaki drew within just 38,000 votes of the opposition.

Hoping to calm tensions, electoral officials suspended the announcement of results for the night.

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Both candidates insisted they were winning, which marks the first time an incumbent has faced a credible challenge in Kenya's four decades of independence from Britain. The unrest, which police said killed several people, tarnished a vote that foreign and domestic observers had praised as calm and orderly.

Two days after the polls, the Electoral Commission said Raila Odinga, the 62-year-old former political prisoner who was the opposition's candidate, was leading Kibaki by just 38,000 votes in 180 of 210 constituencies counted.

The trickle of results ignited tensions in the capital and opposition strongholds Saturday. In Nairobi, the stores that did open Saturday were shutting their doors as the violence escalated, and many people stocked up on food and water.

In the impoverished Kibera slum, Odinga's main constituency, young men with fingers still stained with voting ink were shouting "No Raila, No Kenya!" — an ominous call to declare him the winner. Hundreds of people swarmed out of the slum, heading for town, but police used tear gas to chase them back.

Smoke was billowing out of Kibera as homes, trees and stalls caught fire.

Hamisi Noor, 22, who was standing in front of his burned-out home in Kibera, said a crowd threatened him with machetes before torching his home and slashing his father across the face.

Noor, a member of Kibaki's Kikuyu tribe, said his assailants belonged to Odinga's Luo tribe. "I don't know who they were," said Noor, his trousers covered in blood and mud. "But they were Luos."

Police were blocking off streets as young men climbed billboards to rip down Odinga posters in the capital of Nairobi, about six miles outside the deserted city center.

"Kibaki come back!" the men shouted as they waved machetes and sticks. In another part of the city, police fatally shot two people, according to a police official who asked for anonymity because he was not allowed to talk to the media.

Several diplomats said they feared a narrow victory on either side could lead to rioting by those who do not accept or trust the results. The voting was generally orderly, and no major disruptions were reported. But as the results trickled in slowly, suspicions about rigging flared.

Odinga's Orange Democratic Movement party said the government was deliberately delaying results because Kibaki was losing. Police and electoral officials appealed for calm, saying they were doing their best.

"We may get them (results) tomorrow, the day after tomorrow. It depends on when they come," ECK Chairman Samuel Kivuitu said at a rowdy news conference, in which journalists and others condemned the slow pace.

About 20 miles outside Nairobi, hundreds of people massed along a main highway.

"They are looting houses and stoning cars," Irungu Wakogi, a witness, told The Associated Press by telephone.

In Kisumu, some 185 miles from Nairobi, shops were being looted and the streets were clogged with protesters.

"People are demonstrating because of the delayed announcement," said Grace Kaindi, a police official in the city.

Kibaki, 76, has been credited with helping boost this East African nation's economy, with a growth rate that is among the highest in Africa and a booming tourism industry. But his anti-graft campaign has largely been seen as a failure, and the country still struggles with tribalism and poverty.

If Kibaki loses, he will be Kenya's first sitting president ousted at the ballot box.

Kibaki won by a landslide in 2002, ending 24 years in power by Daniel arap Moi, who was constitutionally barred from extending his term. Moi's blanket use of patronage resulted in crippling mismanagement and a culture of corruption that plunged Kenya into an economic crisis.

In order to win, a presidential candidate must get the most votes as well as garner at least 25 percent of votes in five of Kenya's eight provinces, a move aimed at ensuring a president has some support in most of the country and its many tribes.