Afghanistan's Election Complaints Commission says it will have to clear 650 serious complaints before results of voting for president can be certified this month. Meanwhile the Independent Election Commission, which is counting the votes, says results from nearly 500 polling stations have been invalidated.
The mass disqualification of votes comes as officials in Kabul continue to release - behind schedule - partial and preliminary results of the August 20 election. So far, the incumbent, President Hamid Karzai has a comfortable lead over his closest challenger, former foreign minister Abdullah Abdullah.
Mr. Karzai's tally is still below the more than 50 percent he will need to avoid a runoff election. His re-election bid is being tarnished by reports of massive ballot-box stuffing by his supporters, who also allegedly created fake polling sites.
The Karzai campaign accuses other candidates of also manipulating votes.
The outcome of the vote could still be a couple of months away, if fraud allegations are not quickly resolved or a second round of balloting is called.
Once a clear winner has been determined, international leaders are expected to convene a United Nations conference to discuss Afghanistan's future. A formal call for such a meeting has now been made by Britain, France and Germany.
Afghanistan's fate looks increasingly unclear despite the presence of about 100,000 foreign troops in the country that are fighting the Taliban. Planning for the conference comes as the supreme commander of those NATO-led and U.S. forces, General Stanley McChrystal, is reviewing the overall military strategy.
British Prime Minister Gordon Brown, with the German Chancellor at his side in Berlin, told reporters Sunday this is an appropriate time for an overall assessment of Afghanistan.
"The international conference, the high level conference that we propose on Afghanistan, is one that should meet before the end of the year," Brown said. "It should deal with the issues of security, governance and development and it should of course follow the [ISAF commander Stanley] McChrystal review and the work that is ongoing in all our countries to look at the best pathway forward to Afghanistan."
German Chancellor Angela Merkel said it is important to send a clear signal to the Afghans that more responsibility for running and securing their country is coming their way.
Ms. Merkel says it is the intention of the international community "to raise the pressure" on the Afghans to begin taking over step by step.
The Chancellor is also calling for a quick and thorough investigation of last week's NATO air strike on two fuel tankers, which had been hijacked by insurgents in Afghanistan's Kunduz province.
An Afghan rights organization says dozens of civilians died in the attack, which was ordered by German forces. Witnesses say the Taliban allowed villagers to drain the tankers after the vehicles became stuck in the mud during an attempt to drive them across a river.
In Kabul, police say a father, mother and one of their three sleeping children died late Sunday when their house was hit by a rocket. Taliban insurgents have frequently been firing such projectiles into the city but casualties have been rare.
In other developments in Afghanistan, four service personnel of the NATO-led international force in the country have died since Sunday, including at least two Canadians and one American.
The U.S. military Monday has also announced it is investigating an accusation made by a Swedish charity that American troops last week broke down doors and tied up staff members while searching for insurgents at a hospital in Wardak province.