KABUL: Election authorities began delivering ballots with U.N. assistance across Afghanistan on Thursday, as hurried preparations for the Nov. 7 runoff in the insurgency-plagued nation's presidential election got under way.

International election monitors called on authorities to avert the widespread fraud that marred the first round of voting in August. Scores of election staff accused of misconduct have been axed, and new personnel need to be hired.

President Hamid Karzai will face former Foreign Minister Abdullah Abdullah in the runoff. Abdullah announced Wednesday that he was ready to take part, one day after Karzai bowed to intense U.S. pressure and acknowledged he fell short of the 50 percent threshold needed for victory in the Aug. 20 election. U.N.-backed auditors threw out nearly a third of Karzai's votes because of fraud.

In Washington, U.S. officials said a power-sharing arrangement between Karzai and Abdullah to avoid a runoff was still possible, although it would be up to the Afghans.

Organizing the ballot in a little more than two weeks poses a huge challenge. The preparations come amid a growing Taliban insurgency and ahead of mountainous Afghanistan's winter snows, which begin in much of the country around the middle of November.

U.N. planes were providing logistic support to the country's Independent Election Commission, or IEC, flying ballots and voting kits and to provincial capitals, from where they will be delivered by electoral officials to thousands of polling stations by truck, helicopter and donkey, U.N. spokesman Dan McNorton said.

The IEC, the body that runs the elections, is dominated by Karzai supporters. It is under huge pressure to avoid a repeat of the massive fraud that marred the first voting, which discredited the government and threatened to undermine public support for the war in the United States and European countries that provide most of the 100,000 NATO-led troops serving in Afghanistan.

The Washington, D.C.-based International Republican Institute said that insecurity, ballot-box stuffing and the misuse of state resources for campaigning must be addressed in order for the poll to be credible. The U.S. desperately wants a government that is legitimate in the eyes of Afghans and the international community.

Another major U.S.-based monitor, the National Democratic Institute, said more Afghan police and army troops would be needed this time around. The group said that to eliminate so-called "ghost" polling stations, no ballots should be sent to polling centers that are not secured by Afghan security forces and adequately staffed by the IEC.

It also said "polling centers that experienced fraud during the Aug. 20 election should receive targeted IEC scrutiny on election day and during the counting process."

In an effort to tamp down cheating, officials will cut about 7,000 of the 24,000 polling stations which they set up for the August ballot. Some of those stations were in areas too dangerous to protect. Others never opened, enabling corrupt officials to stuff the ballot boxes with impunity. About 200 of the 2,950 district election coordinators will be replaced following complaints of misconduct leveled by candidates or observers, the U.N. said.

Finding replacements for coordinators and poll workers implicated in fraud will be difficult, especially in a country where more than 70 percent of the population is illiterate. The government had to scramble this summer to recruit enough election officials and poll workers, especially at voting stations reserved for women.

It's unclear if they would be able to fill open posts with better-qualified people.

Karzai is widely seen as the front-runner in the Nov. 7 race. But Abdullah could pose a challenge if he was able to quickly build a wider coalition.

Lawmaker and former Planning Minister Ramazan Bashardost, who came in third in the first round, said he had not made up his mind who he would support — if anyone. He said he would meet with his supporters next week to decide, but the choice was between "the worst, and worse than the worst."

Elsewhere, hundreds of angry students in the eastern town of Khost gathered Thursday at a local college and burned an American flag to protest a rumor that U.S. forces had bombed a mosque and burned a copy of the Muslim holy book, the Quran, in nearby Wardak province the week before. Khost's deputy police chief Yacoub Khan said the rumor was a hoax spread by Taliban supporters to stir up trouble and there was no evidence it had occurred. He said the demonstration was peaceful.

Also Thursday, Joint Chiefs of Staff Chairman Adm. Mike Mullen said he hopes the runoff will result in a "level of legitimacy" in Afghanistan.

"Hopefully getting through the elections in the next couple of weeks, we'll be able to have a level of legitimacy that we can use to deal with this government," he said in a meeting with hundreds of solders at the U.S. military headquarters in Seoul, South Korea. "Because without that, I believe we can't succeed."

Meanwhile, NATO defense ministers were expected in Slovakia on Thursday to discuss the war. U.S. Defense Secretary Robert Gates is expected to brief allies in Bratislava about progress in a review of recommendations by American Gen. Stanley McChrystal, the top U.S. and NATO commander in Afghanistan, who has called for more troops to quell the conflict.

U.S. forces said one of their troops died of wounds sustained in a bomb attack in the south on Wednesday. The death brings the total number of Americans killed in the conflict in October to at least 31.