KABUL, Afghanistan -- Afghanistan's presidential elections are headed for a runoff after full preliminary results released Saturday showed the front-runners failed to win to a majority and avoid a second round of voting.
Former Foreign Minister Abdullah Abdullah garnered 44.9 percent of the vote, followed by ex-Finance Minister Ashraf Ghani Ahmadzai with 31.5 percent, said election commission chairman Ahmad Yousuf Nouristan. The candidates are vying to replace President Hamid Karzai, the only president Afghans have known since the 2001 U.S.-led invasion to topple the Taliban's hard-line Islamic regime.
"According to our findings it seems that this election will go to the second round," Nouristani said. "We have a tentative schedule of June 7th to start the second round."
The preliminary results are to be finalized May 14 after investigations into fraud complaints. But those investigations are unlikely to invalidate enough votes change the outcome that points to a second round. Electoral law requires a runoff between the top two candidates if no one gets a majority.
The eventual election winner will oversee a tumultuous period as the U.S. and NATO are expected to withdraw most of their troops from Afghanistan by the end of this year. Karzai, whose relations with Washington have sharply deteriorated, was constitutionally barred from running for a third term
Both Abdullah and Ahmadzai have promised a fresh start with the West and have vowed to move ahead a security pact with the U.S. that Karzai has refused to sign. That pact would allow a small force of American soldiers to stay in the country to continue training Afghan army and police to fight the Taliban.
The preliminary results were from about 6.6 million valid votes counted by the election commission, Nouristani said. He said the commission had invalidated some 240,000 ballots for fraud and other irregularities, and it also further examining ballots from 444 polling stations -- potentially representing more than 200,000 votes -- because of fraud concerns.
While Abdullah was the clear front-runner in the first round of voting, a runoff could involve a completely different picture as both he and Ahmadzai court the six other candidates in the race and their respective support bases.
Zalmai Rassoul, another former foreign minister who placed third 11.5 percent of the vote, could emerge as a kingmaker, as could Abdul Rasoul Sayyaf, an influential former lawmaker and religious scholar who won 7.1 percent.
It is unclear whether Rassoul and Sayyaf could deliver the votes of their supporters, who are largely Pashtuns, the country's largest ethnic group.
If voters follow previous patterns of choosing along ethnic lines, some believe much of the Pashtun vote will coalesce around the candidate who shares their ethnicity in a runoff -- and many Pashtuns do not view Abdullah as one of their own, since he has an ethnic Tajik mother and Pashtun father.
Still, Abdullah -- who was second place to Karzai in the 2009 election -- clearly received some Pashtun support in the first round, and his experienced campaign may draw enough in a second round to put him over 50 percent.