The United Nations on Wednesday urged Zimbabwe's political leaders and Zimbabweans to reject any form of violence after troops opened fire on opposition demonstrators protesting election results.At least three protester were killed in the violence that erupted two days after Zimbabwe's first parliamentary and presidential elections since Robert Mugabe was forced out of the presidency last year."We are concerned about reports of incidents of violence in some parts of Zimbabwe," said UN spokesperson Farhan Haq."We call on the political leaders and the population as a whole to exercise restraint and reject any form of violence while awaiting resolution of the disputes and announcement of the election results."The United Nations reminds all sides of their pledge to hold a peaceful election, he added.Zimbabwean President Emmerson Mnangagwa blamed the MDC opposition party for the violence, accusing rivals of staging a "disturbance of national peace" to disrupt the electoral process.Official results show the ruling Zanu-PF party won the most seats in the parliamentary ballot but the opposition Movement for Democratic Change (MDC) rejected the outcome and charged that there had been fraud.The results of the presidential vote have yet to be released.* To follow the latest on the Zimbabwe elections SIGN UP TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.