Kabul, Aug 19 (DPA) Afghanistan observers say they expect irregularities in the voting for Thursday's presidential elections but added that their concern lies in whether the problems would rise to a level that would impact the credibility of the balloting.

The election has been problematic even to mount in a country plagued by a Taliban insurgency, poor infrastructure and high illiteracy. Not only have Taliban militants vowed to disrupt the voting and retaliate against voters, but more than 3,100 donkeys, have also been dispatched with voting supplies to areas that are otherwise inaccessible.

'If you are talking about free and fair (elections) in terms of an established democracy, then I think that goes beyond the expectations of a country like Afghanistan, in conflict with weak structures and institutions,' said Kai Eide, the UN special representative in Afghanistan.

'This is the most complicated elections I have ever seen,' he said.

He said that while improvements had been made to prevent fraud since the 2004 presidential election, problems would persist.

'Will there be irregularities? Yes, I feel there will,' Eide said.

'I believe and hope with the measures that have been undertaken it will be possible to keep it at the level which will not affect the credibility of the elections.'

Problems identified in the run-up to the voting by the Free and Fair Election Foundation of Afghanistan, an independent election-monitoring group, included voter registration of minors, multiple registration cards issued for one voter and registrations of women based on unverifiable lists provided by their male relatives.

The campaign of former foreign minister Abdullah Abdullah, the main rival of incumbent and frontrunner Hamid Karzai, charged that the number of people registered, 17 million, exceeds the number of eligible voters in a country of an estimated 30 million people, half of whom are believed to be under the voting age of 18.

Abdullah and other presidential candidates accused Karzai's campaign of manipulating the vote, and the spectre of fraud was raised by the former diplomat at a campaign rally this week in Kabul: 'If there is not vote-rigging, the people will win. If your vote is not stolen, you will put an end to this corrupt government.'

At the back of election officials' minds is the June presidential election in Iran and charges made by its opposition that fraud stole the election for President Mahmoud Ahmadinejad. The accusations resulted in deadly protests and some governments refusing to recognise Ahmadinejad's re-election.

Several officials within Abdullah's campaign have predicted street violence while a number of other candidates have warned about post-election implications if Karzai should win.