Kabul Afghanistan's presidential race kicked off Monday as election authorities began accepting the nominations of would-be candidates, the start of a wide-open race whose winner will oversee the final phases of the withdrawal of U.S.-led troops amid a relentless Taliban insurgency.

The first day of registration drew ... no one.

No major candidates are expected to submit their nominations until closer to the Oct. 6 deadline, part of a waiting game to see how the field shapes up.

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The election, set for April 5, will determine who succeeds incumbent President Hamid Karzai, who has in some form or shape led Afghanistan since the Taliban government was ousted in the American-led invasion in 2001. Karzai, who will have served two five-year terms, is barred from running for a third.

Candidates have until Oct. 6 to submit their names and meet election requirements, including depositing a fee of 1 million Afghanis ($18,000) and proving they have the backing of 100,000 people.

At least 20 people have picked up information packages about running for president in recent days, but there were no submissions on Monday, said Sareer Ahmad Barmak, an election commissioner.

Afghanistan Foreign Minister Zalmai Rassoul AP

There are no clear favorites in the race, but speculation in recent days has focused on Foreign Minister Zalmai Rassoul. Rassoul is a former national security adviser with a medical degree who has tended to stay out of the limelight and could end up being a consensus candidate among some of the many political factions in this nation of 31 million.

Other potential candidates include: Abdullah Abdullah, an opposition leader who lost to Karzai in 2009; Ashraf Ghani, a well-known academic and former finance minister with a reputation as a technocrat who also lost the last election; Hanif Atmar, a former interior minister who has grown critical of Karzai; and Farooq Wardak, the education minister who has been involved in efforts to pursue peace talks with Taliban insurgents.

Some speculation also has focused on Abdul Rab Rasoul Sayyaf, an influential lawmaker with a long history as a jihadist and allegations of past links to Arab militants including Osama bin Laden. He would likely be the most controversial candidate, at least among Afghanistan's foreign allies.

Afghanistan is a desperately poor, ethnically fractious country whose economy relies heavily on foreign assistance. Its politics are marked by patronage and alliances among the elite  a demographic that includes warlords and tribal elders who can marshal votes.

But those alliances are very fluid, and so-called political coalitions that have been set up in recent months have quickly experienced fissures. Even within ethnic groups  the population is roughly 42 percent Pashtun, 27 percent Tajik, 9 percent Hazara, and 9 percent Uzbek along with other, smaller factions  there are divisions that make it difficult to predict who will line up with whom.

Afghan President Hamid Karzai Getty

Karzai, who has been accused of being unwilling to crack down on the pervasive corruption in his government, has said he would not endorse a candidate, but his presence is expected to loom large during the campaign.

Also looming are the Taliban, the militant Islamists who ruled the country from 1996-2001 before being overthrown by America after refusing to hand over bin Laden, whose al Qaeda terrorist network staged the Sept. 11 attacks. The Taliban insurgency has strengthened in recent years and seems primed to wreak more havoc as U.S.-led foreign troops finish withdrawing in late 2014, leaving Afghan troops fully in charge.

Whether the election can be held safely is a major concern, as is whether it can be held without fraud. The 2009 elections were marred by allegations of vote-rigging against Karzai's camp.

Thomas Ruttig, an expert with the Afghanistan Analysts Network, said there are already warning signs about how the vote will go April 5, including reports of "many more voter cards in circulation than voters in Afghanistan" and failures to make progress in peace talks with the Taliban.

At this stage, "one has to be doubtful about how reliable these elections will be," he said.