Iranian voters have turned out in large numbers to choose a new president, with long queues outside polling stations.
The 50 million eligible voters had a choice between six candidates to replace incumbent Mahmoud Ahmadinejad in the first presidential contest since his re-election in a disputed poll in 2009.
Polls closed on Friday after the Interior Ministry extended voting for several hours, a move usually cited by authorities as evidence of high turnout.
Of five conservative candidates, only three are thought to stand any chance of winning the vote, or making it through to a second round run-off in a week's time, Reuters reports.
Current chief nuclear negotiator Saeed Jalili, who advocates maintaining a robust, ideologically-driven foreign policy, is seen as the main conservative contender.
The other two, Tehran mayor Mohammad Baqer Qalibaf and former foreign minister Velayati, have pledged never to back away from pursuing Iran's nuclear programme but have strongly criticised Jalili's inflexible negotiating stance.
They face Hassan Rohani, the sole moderate and only cleric in the race. Though very much an establishment figure, suspicious of the West, he is more likely to pursue a conciliatory foreign policy.
The Guardian Council, a state body that vets all candidates, barred several hopefuls, notably former president Akbar Hashemi Rafsanjani, and Esfandiar Rahim Mashaie, a close ally of Mr Ahmadinejad.