TEHRAN, Iran - Incumbent President Hassan Rouhani leads in the Iranian presidential election by over 4 million votes, according to interior ministry which announced the preliminary results Saturday morning local time after counting almost 26 million ballots.
Earlier, the Interior Ministry reported that over 40 million ballots were cast by Iranians on Friday, indicating a turnout of 70 percent.
Millions of Iranians voted late into the night Friday to decide whether incumbent President Hassan Rouhani deserves another four years in office after securing a landmark nuclear deal, or if the sluggish economy demands a new hard-line leader who could return the country to a more confrontational path with the West.
Ebrahim Raisi, a conservative cleric, accused supporters of Mr Rouhani of hundreds of acts of propaganda at voting booths, which are banned under electoral law.
Ahmadi says the Interior Ministry hopes to have final results later Saturday.
Voting had been scheduled to run until 6 p.m. (3:30 p.m. Prague time), but was extended several times because of a "rush of voters" that caused lines to form at polling booths in various parts of the country. Rouhani and Raisi are the main rivals in the race.
Al Jazeera's Jonah Hull, reporting from Iran's capital, Tehran, said that Rouhani, during an "increasingly acrimonious election campaign, alienated a lot of Iran's significant state institutions who may be in no mood to cooperate with him going forward".
By the time of closure of polling stations Rouhani had leading positions in 12 Iranian provinces and Seyed Ibrahim Raisi in 15 provinces.
Most opinion polls had shown Rouhani, 68, ahead of his main challengers but short of the 50% support he would need to win in a first round. He joined the parliament after the revolution and held major posts such as head of the Supreme National Security Council.
Of a total of 25,966,799 ballots that have been count, more than 784,000 (3.02 percent) have been declared spoilt votes.
Analysts expressed caution about how much Rouhani would be able to do to bring about broader reforms, despite his apparently decisive win, given the influence of security hardliners in Iran's hybrid clerical-republican system.
Although Supreme Leader Ali Khamenei did not officially back either of the candidates, it is believed he was leaning toward conservative Raisi.
A Rouhani second term would allow Iran to present its "best face" and protect the nuclear deal by driving a wedge between the United States and other signatories, said Vaez at Crisis Group. Rouhani is also credited with loosening some control over society.