TEHRAN: Iran kept polls in Friday's presidential election open an extra three hours because of high voter turnout, state television reported.

“On the order of the interior minister (Mostafa Mohammad Najjar), the polls will remain open until 9 pm (1630 GMT),” a ministry statement carried by Iranian media.

It was the second extension of polling hours. Earlier, Najjar had announced an additional two hours of voting.

Under Iran's presidential law, polls are open for 10 hours, with a likelihood of extensions.

Safar Ali Baratlou, responsible for elections in Tehran, was quoted by the media as saying that, as of 1400 GMT, “participation (in the province) is higher than four years ago. It will certainly reach 70 percent.” Various officials in other parts of the country reported turnout of at least 70 per cent by 1330 GMT.

In 2009, nationwide participation reached 85 per cent.

Some 50.5 million voters are eligible to vote in the election to choose a successor to Mahmoud Ahmadinejad.

The vote pitches a divided conservative camp against a moderate candidate who enjoys the backing of the reformists.

Iranian supreme leader Ayatollah Ali Khamenei, who votes in the earliest moments after the opening of the polls urged people to vote en masse.

He also attacked US criticism of the presidential poll. Some US officials had said they did not recognise the presidential election, he noted.

“The hell with you... “ who do not agree with the way the election is being run, Khamenei said. “The Iranian people... will do what is in their interest,” he added.

US State Department spokeswoman Jen Psaki, noting the way the field had been narrowed down to six candidates, had told reporters in Washington on Thursday: “By international standards, this election is not free, fair or transparent.