A burqa-clad Afghan pedestrian walks past an election campaign poster of former Islamist warlord, Abdul Rasul Sayyaf, during the first day of the presidential election campaign in Kabul on Feb. 2, 2014. (Shah Marai/AFP/Getty Images)

Campaigning officially started Sunday in the crucial election to choose Afghan President Hamid Karzai’s successor, amid continuing concerns about attacks by the Taliban and the planned withdrawal of most U.S. and NATO troops starting this year.

Eleven men vying to win the April 5 election have just two months to sway voters.

Among the front-runners are two technocrats, Ashraf Ghani and Zalmay Rassoul, who served in key positions in Karzai’s government, which has been in power since the Taliban was ousted in 2001. The election will result in the first peaceful transfer of power through a ballot in the country’s history.

A former foreign minister, Abdullah Abdullah, who ran against Karzai in the 2009 election, and one of Karzai’s brothers, Qayoum Karzai, are also considered leading contenders. Even though his brother is running, the Afghan president has vowed not to take sides in the contest.

Campaign posters and billboards, featuring candidates posing in both traditional and Western outfits, were posted throughout Kabul, and crowds of people, mostly men, listened to speeches by their favorite candidates. At one campaign site, a group of men danced in a traditional manner under mild rain as a loud drum was played.

The start of Abdullah’s campaign was marred by disorder and differences after followers of his running mates, who belong to two separate factions, disagreed on whether to play music or chant “Allahu akbar,” or God is great, witnesses say.

Supporters of Abdullah’s would-be deputies then abandoned the campaign kickoff, leaving the future of the alliance in doubt, supporters say.

Each of the 11 candidates gave a speech, some live on private television stations owned by their running mates, highlighting their strategies should they win the presidency.

Security was tight for most of the candidates, who have been given three armored vehicles and 35 police officers as extra protection amid fear of attacks by suspected Taliban militants or other rival groups.

The resurgent Taliban, which targeted past elections, has threatened to sabotage this one, too.

According to residents, militants have been ordered not to retreat to Pakistan during the winter as they have in the past. There have already been a number of attacks in the past few months against election workers and campaigners by unknown gunmen.

In the latest such attack, two campaign officials for Abdullah were assassinated Saturday in the western city of Herat, one of the more secure parts of the country.

“This incident at the beginning of election campaign is a bad sign as either the security forces are incapable of providing security for the election campaign or they do not take their job seriously,” Abdullah’s spokesman, Sayed Fazel Sangcharaki, was quoted as saying.

Afghan authorities concede that security will be a key challenge for the elections amid fears that voting could be delayed for several months, potentially extending Karzai’s term.

Speaking to a number of European diplomats Saturday, Karzai said the vote will be held as planned.

NATO and U.S. troops played key roles in providing both protection and assistance for past elections, but this time that might not be the case, which adds to questions about safety surrounding the process.

Most coalition troops are set to pull out of Afghanistan by the end of the year. Growing mistrust in recent months between Karzai and Washington has jeopardized a security pact to allow further presence of foreign troops in Afghanistan after 2014, raising more questions about the stability of the next government.

Rife corruption and poor governance have alienated many from their government, and there seems to be less enthusiasm among Afghans to vote in this election.

The country’s next leader will face a number of key challenges, including talks with the Taliban, fighting corruption and building an efficient government in this polarized country.