Zimbabwean presidential and parliamentary elections were “free, honest and credible”, the African Union observer mission’s head has said.
Olusegun Obasanjo said the incidents reported during Wednesday’s poll could not “change the outcome”.
The largest observer group said earlier the poll was “seriously compromised”.
President Robert Mugabe’s party is claiming victory in the election, which was rejected as a “huge farce” by PM Morgan Tsvangirai.
On Wednesday, voters were choosing a president, 210 lawmakers and local councilors. The Zimbabwe Electoral Commission (ZEC) has five days to declare who won the poll.
First official results from national assembly elections show that Robert Mugabe’s Zanu-PF party is taking an early lead. However, the seats announced were mostly in Robert Mugabe’s rural strongholds, correspondents say.
Zanu-PF spokesman Rugaro Gumbo predicted that Robert Mugabe – who is running for a seventh term – would get at least 70% of the vote in the presidential poll.
“We are expecting a landslide victory,” he was quoted as saying in Zimbabwe’s state-run Herald newspaper.
Zanu-PF and Morgan Tsvangirai’s Movement for Democratic Change (MDC) have shared an uneasy coalition government since 2009 under a deal brokered to end the deadly violence that erupted after a disputed presidential poll the previous year.
Speaking in the capital Harare on Friday, Olusegun Obasanjo said the elections were fair and free “from the campaigning point of view”.
The former Nigerian president admitted that there were “incidents that could have been avoided”, but he stressed that the AU observers did not believe they could change the overall outcome of the poll.
His assessment sharply contrasted to that by the Zimbabwe Election Support Network (ZESN) – the largest group of domestic monitors.
It said on Thursday that the elections were “seriously compromised”, with as many as a million people being unable to cast their ballots.
The ZESN said potential voters were much more likely to be turned away from polling stations in urban areas, where support for Morgan Tsvangirai is strong, than in Robert Mugabe’s rural strongholds.
The group also alleged significant registration irregularities before the poll.
But speaking to al-Jazeera, Olusegun Obasanjo questioned ZESN’s conclusions, describing them as “not verifiable”.
He said he was satisfied that the apparent anomalies between registration between urban and rural voters mentioned by ZESN had been explained by the registrar-general, who had the accurate figures for birth and death.
Olusegun Obasanjo also said that Morgan Tsvangirai’s camp should have addressed concerns about the electoral roll before the vote – not after.
On Thursday, Morgan Tsvangirai said the elections were “null and void”.
“Our conclusion is that this has been a huge farce. The credibility of this election has been marred by administrative and legal violations which affected the legitimacy of its outcome.
“It’s a sham election that does not reflect the will of the people.”
Another observer mission – the Southern African Development Community – is expected to give its verdict on the elections later on Friday.
It is illegal to publish unofficial election results in Zimbabwe. Police have warned they would take action against anyone trying to leak early results.
Extra units – some in riot gear – have now been deployed in Harare.
Under the electoral law, if no presidential candidate gains 50% of the ballots, a run-off will be held on September 11.