PORT-AU-PRINCE - Haiti called off its presidential election on Friday, two days before it was due, over concerns of escalating violence sparked by the opposition candidate's refusal to take part in a process he said was riddled with fraud.Pierre Louis Opont, president of Haiti's electoral council, said the runoff vote was being pushed back for security reasons. But he did not say when the election, already postponed twice before, would be rescheduled.The announcement led to jubilation from demonstrators marching to oppose the election. They danced on the streets of the capital Port-au-Prince, but the mood quickly darkened. Gunshots were fired as protesters clashed with police.The postponement is nevertheless expected to ease unrest after days of protests in the deeply impoverished country of about 10 million people, at pains to rebuild from a devastating earthquake six years ago and to emerge from decades of political dysfunction.Several western nations, fearing a new era of instability in the Caribbean nation, have been assisting Haiti in its election preparations. The US government alone has chipped in $30 million.But opposition candidate Jude Celestin said last week he would not take part in the election, alleging a first round vote in October was rigged to favor the ruling party candidate."The fact that the electoral council was forced to give up the electoral farce is a victory for the Haitian people," said Jean-Charles Moise, another opposition candidate who said fraud led to his first-round defeat.