HARARE, Zimbabwe — Zimbabwe's elections received cautious approval Friday from two African observer missions despite allegations by the main challenger to President Robert Mugabe and a local monitoring group that the vote was heavily rigged. The African Union said it had some “grave” and “serious” concerns, and regional monitors from southern Africa said that while Wednesday's vote was peaceful it was too early to pronounce it fair. Olusegun Obasanjo, head of the African Union mission, said his monitors noted some apparent irregularities but that they did not constitute evidence of systematic tampering. Mugabe's supporters have rejected allegations of rigging and claimed victory. Wednesday's contentious vote has created fresh uncertainty in a country long afflicted by division and economic turmoil. “Yes, the election is free,” Obasanjo said. He described the vote as credible unless any evidence to the contrary emerges, and asked election authorities to investigate reports that tens of thousands of eligible voters were turned away. Another poll monitoring group in Zimbabwe said as many as 1 million of the more than 6 million eligible voters were prevented from casting ballots. “If 25 percent were not allowed, then, yes, the election is fatally flawed,” said Obasanjo, a former Nigerian president. His mission has 70 observers. The head of the observer mission for the Southern African Development Community, a regional body, described the election Wednesday as “very free” and “very peaceful,” but noted that there were some violations and a full analysis was still under way. It was too early to describe the vote as “fair,” he said “The question of fairness is broad and you cannot answer it within one day,” said Bernard Membe, who is also Tanzania's foreign minister. “And so be sure that within 30 days, through our main report, the question of fairness may come.” Mugabe's ZANU-PF party said Friday that poll returns showed that 3.9 million voters cast their ballots on Wednesday. That 61 percent turnout was higher than in an uncontested referendum on a new constitution in March where no disputed voters' lists were used and only national citizens' identity documents were needed. By later Friday, official results announced by the election commission showed President Robert Mugabe's party has won at least a two thirds majority in parliament, enough to amend the country's constitution, according to a tally of official results Friday. With over 180 seats declared by the Zimbabwe Electoral Commission, Mugabe's ZANU-PF had won 142 seats in the 210-member chamber. Full results on the presidential and parliament votes have been promised by Monday. Mugabe's Justice Minister Patrick Chinamasa said Friday his party was “headed for an unprecedented landslide.” — AP