Kabul  - Afghan President Hamid Karzai's challenger in the presidential run-off election was expected to announce this weekend whether he would boycott the poll scheduled for November 7.

Abdullah Abdullah, a former foreign minister, hinted this week that he might withdraw from the second round unless three cabinet ministers including the interior minister were suspended, and the head of the Independent Election Commission (IEC) was dismissed.

Abdullah, who finished second in the August 20 presidential election, said that he set the conditions to avoid a repeat of the fraud which marred the August 20 election.

A UN-backed investigation rejected nearly 1 million fabricated votes from Karzai's tally, pushing the election to a run-off.

Afghan government officials have said that Abdullah's demands were not practical, while the IEC spokesman has said that no candidate could remove the commission chief. Abdullah has accused IEC head Azizullah Ludin of bias favouring Karzai.

A source from Abdullah's camp told the German Press Agency dpa on Saturday that the former top diplomat was holding meetings with his advisors and major supporters to consult them before announcing his stance. He has also been meeting with a number of Western officials since Friday, he said.

Citing a Western source, CNN reported on Friday that talks between Karzai and Abdullah have broken down and that Abdullah would likely announce this weekend that he will boycott the run-off vote.

Daoud Ali Najafi, chief electoral commissioner, said Saturday that no candidate could withdraw from the race after his name was printed on the ballot papers. He said the commission had already printed 15 million ballot papers for the two-man race.

The political uncertainty comes amid Taliban threats of attack to stop the second round of the elections. The militants could not stop the first round of the elections, but their assaults scared away voters from polling stations, causing a lower turnout.

At the start of the anti-election operation Taliban militants attacked a UN guesthouse in Kabul on Wednesday, killing 11 people, including five international UN staff. The militant group said that the attacked UN workers were helping convene the fresh vote.

UN Secretary General Ban Ki-moon said Friday that they were not deterred by the attacks.

But he has said that as part of precautionary measures non-essential UN staff working in Afghanistan will be relocated to safer locations and security will be beefed up to protect those working to assist Kabul in the presidential run-off. (dpa)