Afghanistan's election authorities have strongly denied that top officials were guilty of fraud after front-running presidential candidate Abdullah Abdullah made allegations that could upset a smooth transition of power.

Abdullah's fraud claims put him in direct conflict with the Independent Election Commission (IEC), raising fears of political instability as the bulk of US-led troops withdraw from Afghanistan by the end of the year.

Abdullah demanded the dismissal of Zia-ul-Haq Amarkhail, head of the IEC secretariat, over Amarkhail's alleged attempt to remove unused ballots from its headquarters in Kabul on the polling day.

Live Box 201239113414952721

However, AFP news agency quoted Ahmad Yousuf Nuristani, IEC chairman, on Monday as rejecting the accusations against Amarkhail, and stating that the turnout figure was an early estimate that might be adjusted.

Abdullah has also said the IEC's turnout figure of seven million voters in Saturday's run-off election was probably false.

"I strongly reject these allegations," Nuristani said, adding that Amarkhail was stopped by police when he was overseeing the delivery of extra ballot papers to polling stations that had run out.

"It was a misunderstanding between police and our staff," Nuristani said.

"We do not want a crisis for the people of Afghanistan. They are tired of crises."

'Give electoral bodies time'

The dispute erupted despite pleas from the UN, the US and the EU for Abdullah and his poll rival Ashraf Ghani Ahmadzai to give officials time to conduct the count and adjudicate on fraud complaints.

"We continue to feel that it's important to give the Afghan electoral bodies the time they need to do their work in processing the outcome of these elections," Jen Psaki, US State Department spokeswoman, said.

RELATED: Afghans bank future on the next president

A successful election is a key test of the 13-year international military and aid effort to develop Afghanistan since the fall of the Taliban regime in 2001.

First round of Afghan presidential elections were held on April 5.

Abdullah believes fraud denied him victory in the 2009 presidential race, and has often said that only widespread ballot-rigging could stop him from winning this time.

Source: AFP