Taliban militants threatened on Saturday to disrupt the Nov 7 presidential runoff after attacks during the first round of balloting in August kept many voters away from polling stations.
"The Islamic Emirate hereby informs all countrymen not to take part in this US-led election process," a statement posted on the Taliban website said.
"If anyone gets harmed by our mujahedin by participating in this unfortunate process, they will themselves be responsible for that because the mujahedin have repeatedly informed all Afghans of our decision," it said.
The statement claimed that by convening the election, the Western countries whose militaries are deployed in Afghanistan were trying to conceal their invasion and their defeat on the military front.
During the election's first round, insurgents carried out more than 130 attacks, including firing dozens of rockets and unleashing numerous suicide bombers on polling sites to disrupt the vote.
Those attacks did not stop the elections but contributed to the low turnout of 38 per cent of eligible voters.
"Besides implementing old tactics, this time, they (Taliban fighters) would use more new tactics to stop this process of the enemies of Islam and our country," it said.
The statement also called on Taliban insurgents to attack Afghan and Western military bases before the election and to block all highways one day before the polling day.
The threats were one of the numerous obstacles that could undermine the runoff. Afghanistan's Independent Election Commission must dispatch polling kits to the country's 380 districts, access to some of which could be blocked by the onset of winter snows at the beginning of November.
Because of the remoteness of many areas and time constraints, the commission is having to rely more on airplanes to deliver the kits, replacing trucks and around 3,000 donkeys used in the first round to transport election materials.
President Hamid Karzai, who had claimed an outright victory in the first round, bowed to intense pressure from the US and other Western supporters of his government to allow the two-man runoff after a UN-led fraud investigation team found about one million ballots cast for him were fabricated.
The runner-up in the first round, Abdullah Abdullah, Karzai's former foreign minister, previously accused both the incumbent and the commission of engineering the fraud and has voiced concerns about a repeat of rigging in the runoff.
Abdullah's spokesman has threatened that his candidate might pull out of the elections if top commission members were not replaced. The six-member commission was appointed by Karzai and is widely accused of being biased in favour of the president.
The US government and other Western allies that have troops in Afghanistan hope that the fresh vote would restore the credibility of the elections and produce a legitimate government in Afghanistan that could partner with them in the fight against a resurgent Taliban.
There has been heated deliberations in Washington on sending additional US troops to Afghanistan as demanded by NATO's top commander in the country, but President Barack Obama has said no extra soldiers would be deployed until the new government in Kabul is formed.
Nearly 200,000 Afghan security personnel and more than 100,000 NATO-led international troops are to provide security for the November polling.