Millions of voters across Iran continue to cast their ballots in the country's presidential elections, after the interior ministry extended polling for the third time to allow more people to vote.
Polling stations were originally set to close at 6:00pm local time (13:30 GMT) on Friday, but voting has been extended for the third time until 11:0pm local time (18:30 GMT), according to Mehr news agency.
Earlier, Mostafa Moammad Najar, Iran's interior minister, told the Fars news agency that the voting hours had been extended because of a "rush of voters".
At the same time as choosing a new president from six candidates, voters will also pick municipal councillors.
There are more than 50 million eligible voters, with 130,000 ballot boxes in more than 60,000 voting stations. The first results are expected at the end of Friday or early on Saturday.
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Several witnesses, who visited polling stations in Tehran earlier on Friday, there were more people waiting to vote than at the previous election in 2009, according to Reuters.
Iran's supreme leader Ayatollah Ali Khamenei, who called for a large turnout but did make his preference public for any single candidate, cast his ballot in the capital Tehran at the Hosseini Imam Khomeini Mosque in the Beit Rahbari compound early on Friday.
"Among those running ... I had someone in mind who I chose. I haven't told anyone [of my vote]," he told state television as he voted.
"Even those close to me like my family and children don't know who I voted for."
Khamenei derided Western misgivings about the credibility of the vote.
"I recently heard that someone at the US National Security Council said 'We do not accept this election in Iran'," he said. "We don't give a damn."
Presidential candidate and moderate Muslim leader Hassan Rouhani has also cast his ballot in Tehran.
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"I have come to destroy extremism and when I see that these extremists are worried by my response and my vote I am very happy. It means that with the help of the people we can instill the appropriate Islamist behaviour in the country," he said after voting.
If no candidate secures 50.1 percent or more of the votes to win outright, a second round will be held a week later.
Al Jazeera's Soraya Lennie, reporting from Tehran, said that while the elections have been a little bit more subdued compared to four years ago, people have been arriving quite early and lines are already forming outside the voting stations.
With the conservative camp divided, reformists seem confident of a good showing by Rouhani, the former chief nuclear negotiator, who has emerged as a frontrunner. According to analysts, there is a possibility of a run-off.
|Presidential candidate Hassan Rouhani casts his ballot in Tehran.
Lennie said that Rouhani was earlier not thought of as a serious contender, but since the endorsements of two former presidents, pro-reform Mohammad Khatami and pragmatist Akbar Hashemi Rafsanjani, there had been increasing excitement in Tehran over his candidacy during the past 24 hours.
A group of three heads the conservative camp: former foreign minister Ali Akbar Velayati, Tehran Mayor Mohammad Baqer Qalibaf and the republic's chief nuclear negotiator, Saeed Jalili.
Both sides, reformist and conservative, have appealed for the electorate to turn out in high numbers - the first hoping for change, and the other to show the power of a regime accused of seeking to ensure victory for a Khamenei loyalist.
For both camps, the important issue will be to mobilise abstentionists who demonstrated against Ahmadinejad's re-election in 2009, alleging massive electoral fraud.
The authorities cracked down hard on street unrest started by that result, leading to the eventual detention under house arrest of two reformist candidates, Mir Hossein Mousavi and Mehdi Karroubi.
Follow in-depth coverage of Iran's presidential poll
Campaigning this time has been dominated by two issues: Iran's nuclear ambitions and a devastated economy hit hard by international sanctions because of the atomic programme.
Inflation is raging at more than 30 percent, the rial has lost nearly 70 percent of its value, and unemployment is rising.
Both Western powers and Israel accuse Tehran of seeking to develop atomic weapons under the guise of a civilian nuclear energy programme, a charge Iran denies.
Neither the US nor Israel has ruled out taking military action against Iranian nuclear facilities.
Regional tensions have also soared over Iranian support for Syria's President Bashar al-Assad, an important ally whose government has faced an uprising for more than two years.