The vote to replace Afghan president Hamid Karzai is underway.
It is the first democratic transfer of power since the fall of a Taliban regime in 2001.
Voting was mostly peaceful in the first few hours with only isolated attacks on polling stations.
The most serious attack was an explosion at a polling station in the southeastern province of Logar in which four voters were wounded.
In the northern province of Faryab police said they had arrested a would-be suicide bomber trying to enter a polling station, while in Ghazni, in the southeast, several rockets were fired but landed far from a voting centre.
Taliban insurgents have vowed to derail the process, branding it a US-backed sham.
In Kabul, voter Mohammad Zaki explained why he was taking part: “I came here today to vote and chose the leader of Afghanistan. I believe that the future of Afghanistan is in the hands of the young generation, that is why I’m participating. There is no security concern.”
Karzai himself said: “I urge the people of Afghanistan once again to come out and vote for their candidate, despite the cold and the rain and the threats by our enemy.”
Karzai is barred by Afghanistan’s constitution from running for the presidency again. But, after 12 years in power, he is widely expected to retain influence through politicians loyal to him.
They make up the favourites in this election, including two former foreign ministers – Abdullah Abdullah and Zalmay Rassoul – and former finance minister Ashraf Ghani
The 12 million eligible voters – out of a population of 30 million – have eight candidates to chose from.
The voting has been taking place amid massive security with 350,000 Afghan troops on duty, guarding against attacks on polling stations and voters.
The hope is the election will be better run than the chaotic 2009 vote that handed Karzai a second term amid massive fraud and ballot stuffing.
If no one candidate gets over 50 percent of the votes there will be a second poll at the end of May, and it could take months – perhaps even until October – for a winner to be declared.
Although Karzai’s departure is a turning point for Afghanistan, none of his would-be successors would bring radical change, Western diplomats has said.
A long delay could leave a political vacuum in which the Taliban could gain ground.
It would also leave little time to complete a pact between Kabul and Washington to keep up to 10,000 US troops in the country, to back Afghan forces in the fight against the Taliban.