Kenyan opposition leader Raila Odinga called on Sunday for the government to concede defeat or allow a re-count of a presidential election, saying the government had lost 'all legitimacy' due to fraud.

'If need be, he should resign,' Odinga told a news conference. 'We do not want to plunge this country into chaos.'    

Election officials convened to give final results of the vote as unrest simmered after a chaotic count marred by widespread ethnic violence and allegations of rigging.

Odinga, leader of the Orange Democratic Movement (ODM), questioned why his initial strong lead in Thursday's election counting had suddenly narrowed.

'We will not accept cooked figures ... This government has lost all legitimacy and cannot govern.'    

In the western opposition stronghold of Kisumu, police fired in the air to disperse small groups of youths, witnesses said, as they tried to head off a second day of looting and arson there.

Several people were killed across the east African nation on Saturday in clashes that dented Kenya's reputation as an oasis of stability in a volatile region.

Latest results released on Saturday showed President Mwai Kibaki, 76, taking the lead, infuriating supporters of Odinga, who led in earlier tallies and most pre-election opinion polls.

With the final outcome about to be announced by the Electoral Commission of Kenya (ECK) at a conference centre ringed by armed guards, opposition officials huddled together while Kibaki's men laughed as they waited.

Speculation among foreign diplomats and Kenyan media was rife Kibaki might opt to be sworn in as early as Sunday afternoon, if he wins -- but State House denied that.

'We are in very little doubt there has been rigging,' said one election observer on condition of anonymity.

'If Kibaki wins, they will want to move quickly. They will want to be in government straightaway to deal with any violence.'    

Tension was palpable in the Nairobi conference centre where a day before Odinga allies heckled the head of the electoral commission as he tried to read out figures giving Kibaki a lead of some 120,000 votes.

An earlier official tally gave Odinga a 38,000 vote lead.

'There is a massive question mark over the tally of votes,' chief EU observer Alexander Graf Lambsdorff told Reuters.

'Our observers have been sent away from tallying centres without being given results. In Mombasa, none of the results were being displayed at the tallying centres.'    

He also said there was concern over voter turnout figures in some areas, including Kibaki's Central Province where two polling stations recorded a 98-99 percent showing, and Odinga's Nyanza homeland.

Worries about the vote counting have cast a shadow over Thursday's elections that were initially praised by foreign observers and billed by some as a model for the continent. Odinga supporters set fire to a car in a Nairobi suburb on Sunday as envoys, foreign monitors and local media urged calm.

'The ECK, Kibaki's Party of National Unity (PNU) and Odinga's Orange Democratic Movement (ODM) on the one hand, and the citizens on the other, must all make sure Kenya does not burn,' the Sunday Standard newspaper said in an editorial.

'The country is bigger than all of us.'    

Former colonial power Britain said it was disturbed by the violence and urged all politicians to act responsibly, while Washington asked candidates to accept the electoral commission's final result.

'This is a pivotal moment for Kenya. It is vital the entire election process meets the expectations of the Kenyan electorate,' British Foreign Secretary David Miliband said.

'The international community hopes Kenya will live up to both the letter and the spirit of its democratic principles