U-N Secretary General Kofi Annan has called on the people of Zimbabwe to refrain from violence in the wake of this week's controversial election won by President Robert Mugabe.

Mr. Annan said Wednesday he is anxious about the situation in Zimbabwe following the vote widely condemned as unfair. The U-N secretary-general said he has received conflicting reports on the way the election was run and he needs a more definitive assessment of how the polling and vote counting was conducted.

Mr. Mugabe's challenger, Morgan Tsvangirai, has rejected the election result. He says Mr. Mugabe's supporters intimidated opposition voters and stuffed ballot boxes to rig the outcome. The government denies those charges.

Election officials in Zimbabwe say President Mugabe won re-election with about 55 percent of the vote -- to maintain his 22-year grip on power. They say Mr. Tsvangirai received 40 percent.

Observers from the Organization of African Unity say the election was free and fair. Observers from South Africa gave the elections qualified support, calling it legitimate but refraining from describing it as free and fair.

The United States, Britain and other Western countries say the election was not legitimate. U-S officials say Washington is considering further sanctions against the Mugabe government.

Britain, Zimbabwe's former colonial power, also condemned what it called a systematic campaign of repression by the government.