Iranians vote for new president
Although all six candidates are seen as conservatives, one of them, cleric Hassan Rouhani, has been reaching out to the reformists in recent days.
The election will decide a successor to outgoing leader Mahmoud Ahmadinejad.
His eight years in power have been characterised by economic turmoil and Western sanctions against Iran over its controversial nuclear programme.
Some 50 million people are eligible to cast their ballots. Polls across Iran opened at 8 a.m. and were due to close at 6 p.m.
However, the Iranian Interior Minister, Mostafa Mohammad Najjar, announced that voting time will be extended for another two hours.
In some parts of the country more ballot papers have been requested.
Ballot counting is still expected to start at midnight local time and results are due to be announced in the following 24 hours.
The minister also told state TV that presidential candidates would have three days to lodge complaints to the vetting body, the Guardian Council, if they were unhappy with the results.
Mahmoud Ahmadinejad cast his ballot in Tehran accompanied by Vice-President Mohammad Reza Rahimi and Government Spokesman Gholam Hoseyn Elham, Iran’s Fars news agency reported.
The past week brought a surprising change to what otherwise had looked like being a predictable election, the BBC’s Richard Galpin reports.
Rouhani has been attracting increasing attention, speaking publicly about the need to re-engage with the West, our correspondent says. (BBC)