Afghan President Hamid Karzai holds up his inked stained finger after voting in the presidential election in Kabul. (REUTERS)

KABUL (AFP) — Nervous Afghans prepared to elect a president on Thursday, reeling from a surge in Taliban attacks as the government lashed out, threatening to expel foreign journalists who report violence on polling day.

Security forces went on high alert following a barrage of attacks waged by the Islamist militia in a bloody countdown to Afghanistan’s second presidential election, eight years after the US-led invasion ousted the Taliban regime.

Western-backed President Hamid Karzai hopes to win by a big enough margin to avert a run-off vote, but his government ordered a media blackout for fear that reporting of the violence could hurt turnout among the 17 million voters.

“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,’’ Karzai urged on the eve of the polls.

Claims of vote-buying have fuelled concerns about the credibility of the election, along with rampant corruption and Karzai’s reliance on fractious warlords who stand accused of rights abuses.

On Wednesday, police fought pitched gunbattles with Taliban gunmen who stormed their way into a Kabul bank building, afterwards dragging out the blackened and bloodied bodies of three attackers.

“We have killed three of the attackers,’’ Kabul criminal investigation police chief Sayed Abdul Ghafar Sayedzada told AFP. “They were Taliban,’’ he said.

The Taliban claimed responsibility for the siege, which they called part of a series of attacks designed to sabotage Western-backed moves to install democratic order in one of the world’s most lawless nations.