KABUL, Afghanistan (CNN) -- Afghan President Hamid Karzai leads his rivals as votes are counted in the country's presidential election, election officials announced Wednesday.
Afghan election workers tally voting results at the election commission headquarters in Kabul.
Karzai has 422,137 votes, compared to 330,711 for his nearest challenger, his former foreign minister, Abdullah Abdullah. Ramazan Bashardost trailed a distant third, with 108,156 votes.
Only 17.2 percent of the ballots from the August 20 election have been counted, the Independent Election Commission said. Final results are not expected until September.
Candidates must get 50 percent of the vote to avoid a run-off. If no candidate wins an absolute majority, there will be a run-off between the top two contenders, most likely in mid-October.
Abdullah has accused the incumbent of rigging the elections in his favor. Six other presidential candidates have also called for an investigation into "widespread fraud and intimidation" that they said could cast doubt on the legitimacy of the vote.
Only Abdullah accused Karzai of having a role in the alleged fraud.
America's top diplomat for Afghanistan and Pakistan, Richard Holbrooke, tried to downplay the post-election dispute, calling it "politics, Afghan-style."
Holbrooke urged election observers to wait for Afghanistan's Electoral Complaints Commission to conclude its investigation into allegations of fraud.
He spoke to CNN's Ivan Watson on the sidelines of a ministerial meeting in Istanbul, Turkey, on Tuesday.
"We should not be surprised that democracy is imperfect even in Western countries," he said. "And Afghanistan has had unique difficulties in holding this election. So let's see what happens."
Holbrooke also stressed that it is still too early to declare victory in Afghanistan.
"This election is not over," he said, adding that no one could declare a winner until the counting of ballots and evaluation of complaints of fraud were completed.
Before voting even began last Thursday, opposition candidates were accusing the Karzai campaign of rigging the election.
Abdullah repeated those allegations in an interview with CNN in Kabul this week. He told CNN's Atia Abawi that his campaign had received what he described as credible reports of fraud in the southern provinces, where security was poor and turnout less than 10 percent.
Abdullah said ballot boxes were stuffed with additional votes, with 90 percent of them going to Karzai.
"This is stealing the elections, and it will not be accepted," he said. Abdullah explained that he based his allegations on accounts of witnesses and on videos, but no videos were made public nor was it clear whether any had been turned over to the organization investigating election complaints.
A spokesman for Karzai's presidential campaign, Waheed Omar, said the allegations were without merit.
"This is an all-out propaganda war that is undermining the process of the ECC (the Electoral Complaints Commission) by bypassing the legal institutions and making it an all out media campaign," Omar said.
The commission investigates complaints of voting irregularities and fraud. ECC officials said that as of Monday, the body had received more than 600 complaints from voters around the country, and officials characterized dozens as being "highest priority" for investigation.