Taliban guerrillas will fail if they try to derail this weekend`s elections in Afghanistan, the government and its U.S. backers said on Thursday.

Militant violence has been the main worry in the run-up to Sunday`s landmark elections for a national assembly and for councils in all 34 of the Muslim country`s provinces.

The hardline Islamic Taliban, who have battled U.S.-led and government forces since being overthrown as rulers in 2001, are opposed to the U.N.-backed polls and have killed several candidates, but have pledged not to attack polling stations.

Interior Minister Ali Ahmad Jalali said police had foiled more than 100 insurgent plots in the past month, including plans for bombings and suicide attacks, and had arrested a number of people including some foreign nationals.

"The enemy will try before and during the elections to bring about a situation to frighten people," he said. But he added they did not have the resources to "block the election process".

As he spoke, news came through that a woman candidate campaigning in the east had been shot and wounded.

Thursday was the last day of the campaign. Candidates` vehicles covered in posters and with loudspeakers blaring crawled through Kabul`s clogged and dusty streets.

U.S. ambassador Ronald Neumann said the vote might not be perfect, but would still represent a historic achievement.

"I think it is very likely there will be some violence," he told reporters. "I can`t rule out that there could be some large violence, but I don`t think there will be any kind of violence that will stop the success of the election."

Surge in Violence

More than 1,000 people have been killed in the run-up to the vote, most of them militants but including 49 U.S. troops. It has been the bloodiest period since the Taliban`s fall.

About 100,000 troops, including 22,000 U.S.-led troops and 10,000 NATO-led peacekeepers, will provide security for up to 12.5 million Afghans to vote.

The U.S. lobby group Human Rights Watch said intimidation by insurgents and warlords -- some of whom were standing for election -- had undermined the campaign, and that international forces should not cut troop levels too quickly after the polls.

The United Nations said it too was worried about attacks, but that Afghans had nevertheless been able to exercise their political rights.

The elections are being held on a partyless basis, with all candidates standing as independents, and an electoral system that gives voters only one vote in multi-member constituencies.

Critics say the system can be unrepresentative. One think-tank calls it a lottery.

Emma Bonino, a former European commissioner heading an EU observer mission, told Reuters: "It is the long-standing position of the European institutions that the system is not conducive to creating a viable political organisation ... but I have a positive expectation."

A spokesman for the governor of Nuristan province in eastern Afghanistan confirmed Wednesday`s attack on Hawa Nuristani, a woman contesting a national assembly seat.

"She`s OK now, she`s in stable condition," he said, adding that she been wounded on her arms and the side of her head.

On Wednesday night, security forces killed three Taliban fighters in the insurgent-troubled central province of Uruzgan, bringing the number of deaths there to at least 13 in 24 hours.

Taliban spokesman Abdul Latif Hakimi confirmed the losses, but said the guerrillas had killed seven police.