An Iranian groom talks with his bride as they arrive Friday at a polling station to vote for the presidential elections in downtown Tehran, Iran. Iranians packed polling stations from boutique-lined streets in north Tehran to conservative bastions in the countryside Friday.

Tehran, Iran ? Iranian news media this morning reported a huge, unexpected election victory for Iranian President Mahmoud Ahmadinejad, giving him nearly two-thirds of the vote, far above challenger Mir Hossein Mousavi.

With about 29.6 million votes counted — more than 90 percent of those cast — Ahmadinejad was leading with 19.7 million votes, or about 66.5 percent, to Mousavi’s 9.8 million votes, about 33 percent.

The reported result is bound to prompt charges of a stolen election from supporters of Mousavi and other opponents of Ahmadinejad.

Mousavi, a former prime minister, said in a Friday evening press conference that he had won, and he charged there were a number of election irregularities.

The competing claims raised the stakes further in an unprecedented contest that’s polarized the country.

Iranian citizens — new voters, rare voters and reliable voters — flocked to the polls as they opened Friday morning, men and women waiting in separate lines outside Tehran polling stations for an hour or more to vote. Polls had been scheduled to close at 6 p.m. local time, but voting hours were extended until midnight.

The election has mesmerized the nation, exposed deep class divides in Iranian society and at times indirectly touched on the country’s tightly run theocracy. It has already widened — at least temporarily — the space for political debate in Iran and raised hopes in the U.S. of an eventual U.S.-Iranian dialogue along the lines suggested by President Barack Obama, although its effect on Iranian policies remains to be seen.

In Washington, Obama said he was “excited” to see the “robust debate” in Iran and thought this would give a boost to U.S. aims to resolve differences with Iran diplomatically.

“We think there’s the possibility of change,” he told reporters. “Ultimately, the election is for the Iranians to decide. But you’re seeing people looking at new possibilities.”

At 6:30 p.m., a half-hour after polls were to close, men and women still waited in lines to vote at polling stations in central Tehran, and authorities several times announced extensions of voting hours.

With tensions running high, Mousavi’s advisers complained of what they said were several suspicious developments. Cell phone text messages, a ubiquitous form of communication among young urbanites in Iran, couldn’t be sent on Friday.

Rumors spread that pens provided at polling stations were filled with disappearing ink, and partisans of Mousavi and reformist cleric Mahdi Karroubi urged one another to bring their own writing instruments. In Iran, voters write in the names of their candidates of choice.

Some of the reports couldn’t be independently verified, and Interior Minister Sadeq Mahsouli disputed that there were problems. “The enemies of our nation were trying to decrease the participation of the people by spreading rumors that the election is not healthy,” Mahsouli said, according to the quasi-official Mehr news agency.

Supreme leader Ayatollah Ali Khamenei, who holds ultimate power in Iran, especially over security and foreign policy matters, urged voters: “Don’t pay attention to the rumors,” as he cast his ballot in front of television cameras.

Overall, the mood at polling places seemed buoyant, expectant and intensely patriotic.

Obama’s outreach to Iran wasn’t the dominant topic for voters, but even some Ahmadinejad supporters said the U.S. president’s words, particularly his videotaped message to Iran on the New Year holiday of Nowruz, struck a chord.

“That message on Nowruz has lots of influence on Iranian people’s minds,” said Ebraheime Salehvand, 18, who voted for the incumbent in the western Tehran district of Falakey Sadeqiyeh.