Huge security as Afghan presidential election looms
There is a huge security operation in Afghanistan as presidential candidates prepare for Saturday's vote.
The new president will succeed Hamid Karzai, who has been in power since the 2001 fall of the Taliban but is constitutionally barred from seeking a third consecutive term.
It should be the first time that power is democratically transferred.
But pitfalls lie ahead, especially the threat of Taliban violence as Nato prepares to withdraw later this year.Fraud fears
The Afghan election is being protected by the biggest military operation since the fall of the Taliban. Rings of security have been set up around each polling centre, with the police at the centre and hundreds of troops on the outside. Already - a day before polls open, all roads into Kabul have been blocked, and there are many more police checkpoints than usual.
In a meeting with Afghan generals, the commander of international forces General Joseph Anderson said that because the capital is so tightly controlled, there are indications that the Taliban will hit targets outside, in particular in Logar province, just south of Kabul.
General Anderson admitted that the security will not prevent intimidation. But he said that he hoped that social media would play a role in persuading people that it is safe to vote.
Security has been tightened across the country with nearly 200,000 troops deployed to prevent attacks by the Taliban, who have threatened to disrupt the poll.
The BBC's Afghanistan correspondent David Loyn says the election is being protected by the biggest military operation since the fall of the Taliban.
Rings of security have been set up around each polling centre, with the police at the centre and hundreds of troops on the outside.
Reporting restrictions are in place, limiting what can be broadcast about the candidates.
If nobody wins more than 50% of the vote in this round, a run-off election will be necessary.
The BBC's Lyse Doucet in Kabul says that the third presidential race since the fall of the Taliban is certain to be marred by rigging, recrimination and violence.
Our correspondent says that the run-up to this historic poll has already been the bloodiest, and fears of electoral fraud are pronounced.
But a new political culture is slowly emerging, our correspondent says.
There are eight candidates for president, including former foreign ministers Abdullah Abdullah and Zalmai Rassoul, and former finance minister Ashraf Ghani Ahmadzai.
Correspondents say the election may give the US a new chance to repair relations with Kabul, which are moribund after more than 12 years of war and repeated rows between the White House and President Karzai.
Key questions ahead of the vote
- What are the main issues? A final security agreement with the USA is the most pressing issue. All other matters, from trying to bring the Taliban to the negotiating table to fighting corruption and the drugs trade, depend on this
- Will the vote be free and fair? There is widespread concern about ballot stuffing and ghost polling stations - the kind of cheating that has marked every election since 2004
- Is security a major logistical problem? Yes. The Taliban have vowed to disrupt the vote and there were a string of attacks leading up to it. But security at this election will be tighter than in previous votes
- What happens if no-one wins in April? If no candidate wins more than 50% of the vote, the two top contenders will go to a run-off on 28 May. As there is no clear front-runner, in contrast to 2009, a run-off is likely, with final results for the first round not expected until mid-May
A stable and acceptable political transition is "critical to sustaining international support for Afghanistan", White House press secretary Jay Carney said on Monday.
Relations between the president and Washington plunged to new lows late last year when the Afghan leader refused to sign a bilateral security agreement that would allow up to 10,000 troops to stay in his country after the Nato combat mission ends.
The troops staying on would train, advise and assist Afghan security forces and conduct counter-terrorism missions.
Correspondents say that President Karzai is eager to ensure that his legacy does not include a commitment to allow the continued deployment of international troops in his country.
It is unclear what role he sees for himself after the election.
Much may depend on whether a clear front-runner emerges at the head of the eight presidential hopefuls.
However, Saad Mohseni, who heads the Moby Group that includes the popular Tolo TV, said its polls indicated the number of undecided voters may be as high as 30-40%.
With a clear winner in the first round unlikely, a result may not be known until the summer.