KABUL, Feb. 2 -- Afghanistan's third presidential election campaign since the collapse of Taliban regime in late 2001 formally kicked off in the conflict-plagued country on Sunday amid tight security as the militant group vowed to disrupt the polling process.

Supporters of presidential runners have began decorating walls and streets of the Afghan capital Kabul by installing billboards, gluing the posters and pictures of their favorite candidates to muster support.

Nevertheless, the voters, particularly ordinary citizens seem doubtful over the ability of candidates to act upon what they promise to the people.

"I want to use my suffrage, but I don't know to whom I should vote, because in the previous elections we had received a lot of promises by the candidates but have seen little change in our living conditions," Mohammad Sadiq, 38, told Xinhua.

The poor balloon seller said that the candidates in 2009 had promised to create job opportunities for the citizens, improve security and ensure justice but all in vain.

"Security has been deteriorated since 2009. In 2009, I was able to travel around the country without any fear, but today, I am not able to visit my relatives in Hazar district of Logar province. Almost every day, people are killed in suicide attacks and other violent incidents," he said.

"I have no job and no regular income. The only change in my life over the past five years is that in 2009 I had worked with a pushcart but today I am selling balloons on streets to feed my family," Sadiq said.

Insecurity and unfriendly weather in part of the mountainous country remained the main challenges for the two-month campaign ahead of the presidential election slated for April 5.

Eleven candidates including two former foreign ministers and a former defense minister have registered to contest the race.

"Our prime need is ensuring peace and economic stability in the country. All of these candidates were with government one way or another over the past decade. I wonder if any of these candidates is able to bring about viable peace and economic stability," another Afghan citizen Mohammad Ghous told Xinhua.

To ensure the security of the presidential hopefuls, the Interior Ministry has provided three armored vehicles and 35 police to each candidate.

However, Taliban militants denounced the elections as "waste of time" in a statement posted on the outfit's website on Saturday, saying no presidential candidate can escape from death despite security cover.

Amid security threats, unknown gunmen shot dead two election campaign workers of a political party in western Herat province on Saturday evening.

"I don't mind security problems, I will cast my vote on the voting day. However my demand for the next president is to serve the people by fighting corruption, eradicating drug, ensuring justice and properly using international financial assistance to improve living conditions," another Afghan Zabihullah whispered.