Security forces in Afghanistan are on high alert on the eve of the country's presidential election, which the Taliban have vowed¹ to disrupt.

阿富汗安全保卫部队在全国性总统竞选前夕保持高度警惕，此前塔利班曾宣誓要进行捣乱。

The Taliban have vowed to disrupt the elections on Thursday

Some 300,000 Afghan and foreign troops will be deployed² to protect the 17 million voters at 6,969 polling sites.

President Hamid Karzai has urged Afghans to turn out to vote "for the country's stability, for the country's peace, for the country's progress".

Earlier, troops killed three suspected militants³ who attacked a bank in Kabul.

The government meanwhile came under severe criticism for ordering a ban on the media reporting violence on election day.

The United Nations has asked for the ban to be lifted, saying the Afghan constitution guarantees a free press. Some journalists have reported being harassed⁴（疲倦的，厌烦的） and beaten by security forces.

On Tuesday, more than 20 people were killed in attacks across the country, including a suicide bombing in the capital.

'Good for us'

Speaking to reporters in Kabul after a small ceremony marking independence day, Mr Karzai said he wanted every registered voter in Afghanistan to make sure they cast their ballots⁶ in Thursday's presidential and provincial⁷ elections.

"I'm requesting all our people, wherever they are - in villages, in homes, in remote areas, in valleys - to come out and vote in millions to make this country a greater, better success," he said. "It's good for all of us."

"Enemies will do their best, but it won't help," he added.

The UN Secretary-General, Ban Ki-moon said that by participating, Afghans would help "bring fresh vigour⁸（精力） to the country's political life, and ultimately reaffirm their commitment to contribute to the peace and prosperity of their nation".

Opinion polls suggest support for Mr Karzai is at around 45%, with his former foreign minister, Abdullah Abdullah, in second place with 25%.

Preliminary official results should be announced sometime on Saturday evening. If the winning candidate fails to gain more than 50% of the vote on Thursday, there will be a second-round run-off in October.

'Suicide bombers⁹'

Polling stations are due to open at 0700 (0230 GMT), but it is unclear how many will actually operate because of the security threat.

The interior ministry¹⁰ says about a third of the country is at high-risk of attack, and that no polling stations will be open in eight districts under Taliban control.

Additionally, a fifth of polling stations have yet to receive election materials, although officials say they will be fully¹¹ equipped by Thursday morning.

Three election workers were killed by a roadside bomb while delivering ballot⁵ boxes by car in the remote north-eastern province of Badakhshan on Wednesday, while two others died in a similar blast in Kandahar.

Fearing further violence, the local authorities in the city of Kandahar have announced they will close roads to normal traffic.

In a statement, the Taliban said 20 suicide bombers had made their way to Kabul, where they were preparing disruptive attacks.

"The mujahideen will bear no responsibility for whoever gets hurt," it added.

The Afghan government has said that in the "national interest", news media should avoid "broadcasting any incidence of violence" between 0600 and 2000 on election day to "ensure the wide participation¹² of the Afghan people".

The Interior Ministry separately said journalists should stay away from the scene of any attacks until investigators¹³ had collected evidence.

"We will not obey this order. We are going to continue with our normal reporting and broadcasting of news," said Rahimullah Samander of the Independent Journalist Association of Afghanistan.