Afghanistan's President Hamid Karzai saw his lead increase to 46 percent of the vote in the latest batch of results released by the country's Independent Election Commission. That is still below the more than 50 percent he will need to avoid a runoff election with former foreign minister Abdullah Abdullah.

Election officials say they have now processed ballots from more than one-third  of polling stations nationwide and just more than two million votes have been deemed valid.

The director of the Independent Election Commission, Dauod Ali Najafi, announced the vote totals to reporters in Kabul Saturday evening. "Mr. Hamid Karzai has received 940,558 votes," he said.

That equals 46.3 percent of total valid votes tabulated so far.

Challenger Abdullah's 638,924 votes - just over 31 percent. There are a number of other candidates far behind.

Additional, partial results are to be released on Monday.

President Karzai will need more than 50 percent of the vote to avoid a runoff election against the top challenger.

Najafi was asked by a reporter about reports U.S. special envoy Richard Holbrooke is trying to pressure the Afghan government into holding a second round to alleviate concerns of widespread voter fraud.

Najafi says Holbrooke does not have any right to decide whether or not there will be a runoff. If no candidate has more than 50 percent of total valid votes, then there will be a second round of the election.

Both the Karzai and Abdullah campaigns have exchanged accusations of ballot box stuffing. Other presidential candidates have also produced evidence of what they say shows wholesale fraud by officials and campaign workers.

The Election Complaints Commission, partly appointed by the United Nations, has received more than 2,000 formal complaints. It says more than 200 are serious and will need to be investigated before the election results can be certified. That process might take weeks.

Billed as only the second free election for President in Afghanistan's history, the fraud allegations are threatening the legitimacy of the process.

Also complicating the picture is a perception President Karzai, to gain electoral support, has allied with brutal warlords and others accused of either human rights abuses or drug trafficking.

Voter turnout was lower than expected, especially in the troubled south, in part because of Taliban threats to disrupt the balloting and retaliate against voters.

In the latest violence, officials in Zabul province say at least two civilians were killed and 21 wounded Saturda when a suicide bomber in a small town walked up to NATO and Afghan troops patrolling a market.

A roadside bomb struck a convoy Friday in Logar province, killing an American military member and wounding a U.S. radio network reporter.

That attack makes August the deadliest month for U.S. forces in Afghanistan since the Taliban-led government was ousted in 2001.