Millions of Afghans braved Taliban threats Saturday to vote for a successor to President Hamid Karzai in a landmark election held as US-led forces wind down their long intervention in the country.

Polling stations officially closed at 5:00 pm (1230 GMT), officials said, after a day without major security incidents. But voting was set to continue for some time as voters in line at polling stations would be allowed to cast their ballot, a senior official with the Independent Election Commission said.

Security was a major concern following a string of high-profile attacks in the capital Kabul, most recently a suicide bombing at the Interior Ministry on Wednesday that killed six police officers. The Taliban have rejected the election as a foreign plot, and urged their fighters to attack polling staff, voters and security forces.

Afghanistan's third presidential election brings an end to 13 years of rule by Karzai, who has led the country since the Taliban were ousted in a US-led invasion in 2001. The Nato coalition force is pulling out its last 51,000 combat troops this year, leaving Afghan forces to battle the Taliban insurgency without their help.