Johannesburg - Zimbabwe's Vice President Emmerson Mnangagwa on Friday pledged that next year's elections will be peaceful, "free and fair" despite opposition concerns about electoral interference.Speaking on the sidelines of a conference aimed at courting South African investors, Mnangagwa noted that the last election in 2013 "was free of any violent incidents.""We believe that we shall have a free and a fair election during 2018," he told reporters, pledging that the upcoming presidential and parliamentary ballot would, like the last, be "free of violence."Previous elections have been marred by violence against opponents of President Robert Mugabe as well as voter intimidation and alleged fraud.The ruling ZANU-PF party, in power since independence in 1980, has a stranglehold on government and is often accused by the opposition of electoral fraud, voter intimidation and violence.Opposition leader Morgan Tsvangirai believes Mugabe's party has never fairly won any election in recent times."ZANU-PF has not won recent elections, it has rigged them," he told AFP last month, saying he didn't expect Mugabe to come out and commit to "create conditions for free and fair elections."Mnangagwa said political parties had agreed to electoral reforms to "level the playing field" including the creation of voter registers based on polling stations rather than constituency-based rolls.Ahead of the vote, the government will roll out biometric voter registration to create fresh voter lists.Previous ballots have been marred by allegations of the exi'tence of ghost voters, with names listed of people who were long dead, were under age or who never even existed. Opposition parties are trying to forge an electoral alliance in a bid to oust the 93-year-old Mugabe whom the ruling party is fielding.But Mugabe has scoffed at the planned alliance as combination of zeros saying it would make victory easier for his ruling party as it focusses on one common rival rather than separate opponents.ZANU-PF is widely seen as divided over Mugabe's successor, with Mnangagwa seen as one of the favoured replacements along with Mugabe's wife Grace.