Zimbabwe Victor Urges Unity; Rival Challenges Election ResultEmmerson Mnangagwa called Friday on his country to unite, a day after he was declared the narrow winner of Zimbabwe's presidential election, while the opposition leader said the poll was a fraud and pledged to challenge the result. Both Mnangagwa and opposition leader Nelson Chamisa held news conferences in Harare claiming they had won the election, the first poll since longtime leader Robert Mugabe's removal from power. The election commission said Mnangagwa took 50.8 percent of the vote, while Chamisa received 44.3 percent. Because Mnangagwa won more than 50 percent of the vote, he avoids a runoff election. Mnangagwa pledged Friday to be president for all Zimbabweans and said Chamisa would have a vital role to perform in the country's future. Chamisa said his Movement for Democratic Change party wanted a "proper result to be announced.'' "We are not accepting this fiction,'' he said. Chamisa also condemned the killing of six people at an opposition protest this week and said authorities should be held accountable. Chamisa supporters erupt Mnangagwa called for an independent investigation into the election violence, which began when hundreds of Chamisa supporters, angry that announcement of the election results had been postponed, threw rocks at police outside commission headquarters Wednesday. Police responded with tear gas and water cannons. The army was called in, and witnesses said soldiers beat and shot at marchers. In addition to the fatalities, 14 people were wounded. Mnangagwa said the violence was "unfortunate." The United States said Friday that it was reviewing Zimbabwe's election results and called on political leaders to "show magnanimity in victory and graciousness in defeat." The State Department said it would continue to review the data before making "a complete assessment of the overall election." "We encourage all stakeholders and citizens to pursue any grievances peacefully and through established legal channels," the department's statement said. Zimbabwe's election commission has said turnout for Monday's election was high in most provinces, but that a large number of votes had to be rejected. Mnangagwa was vice president and took over for the authoritarian Mugabe after the latter was forced from office last year. Mnangagwa and the ruling ZANU-PF party must try to fix Zimbabwe's ailing economy and poor international image while also dealing with a population demanding change after 40 years of Mugabe.