KABUL: Afghans are awaiting the latest tranche of results from key elections amid concerns that investigations into vote-rigging claims could drag on, creating a dangerous political vacuum.

Up to 99 percent of the laborious ballot count from the August 20 poll is expected to be announced around 5:00pm (1230 GMT), but the winner will not be officially declared until all electoral fraud allegations are resolved.

The final result was originally scheduled for September 17, but with the Independent Election Commission (IEC) warning up to 500,000 ballots could be quarantined, naming Afghanistan's new president still looks weeks away.

The UN-backed Electoral Complaints Commission (ECC) has already ordered thousands of votes thrown out from 83 polling stations in three provinces, but there is no time-scale for investigations in the rest of the country.

The IEC had hoped to announce preliminary results Saturday, but spokesman Noor Mohammad Noor told AFP the count was not complete, in yet another delay to the arduous process.

"We will announce around 99 percent today," he told AFP. "One percent is not processed, it has not been entered into the system."

He was unable to give a time-scale for the full result.

Fraud concerns raised by the ECC include suspiciously high turnout in provinces where Taliban intimidation kept people away from the polling centres, and inordinately high votes for one candidate -- indications of ballot stuffing.

"We are not sure when the fraud allegations will be reviewed, so we are probably heading for another couple of months of this political crisis," said Haroun Mir of Afghanistan's Centre for Research and Policy Studies.

The IEC has been releasing the results piecemeal, with the last batch released a week ago showing incumbent Hamid Karzai with 54 percent of the votes announced so far.

His main rival, former foreign minister Abdullah Abdullah, trails with less than 30 percent and has alleged massive state-engineered fraud in favour of a second five-year term for Western-backed Karzai.

Richard Holbrooke, the US envoy for Afghanistan and Pakistan, told the BBC on Friday that any delays could create an unstable environment in a nation where Islamist insurgents are waging a bloody battle against the government.

"The beneficiary of any delays of the sort you're talking about would be the Taliban and Al-Qaeda, and everybody understands that," he said.

But Nader Nadery, of the Free and Fair Election Foundation of Afghanistan, said the ECC must be given time and resources to do its job.

"The process needs to be worked out. If it is taking a longer time, we should not rush," he said.

The IEC's Noor has said that 447 polling stations, or 200,000 ballot papers, have already been quarantined for investigation by the ECC, with that number expected to rise to 660 polling stations -- up to 500,000 ballot papers.

The presidential and provincial council elections were seen as a key test of Western-backed efforts to bring stability to Afghanistan eight years after a US-led invasion overthrew the Taliban regime.

But instead of emerging from decades of war, increasing attacks by the regrouped Taliban have hobbled development, while about 100,000 US and NATO troops are in the country backing up government forces.

Military commanders are expected to ask President Barak Obama for more troops in Afghanistan, though senior lawmakers in Washington have warned that opposition to a fresh military build-up is growing.

On Friday, seven Afghan police were killed in a Taliban raid on their post in northern Kunduz province, the local governor said.

A roadside bomb also killed six civilians in southern Kandahar on Friday, while two children were killed and two others wounded in a similar blast in eastern Khost province, police and local officials said.