Millions of Iranians joined long queues to vote on Friday, a sign of strong turnout in an unexpectedly tight presidential election that could determine the future of the country’s nascent emergence from international isolation. Shortly before polls were due to close, state television reported that voting had been extended by at least two extra hours to 8:00 pm (1530 GMT) to cope with a "rush of voters". The presidential vote pits incumbent Hassan Rouhani, who wants to normalize ties with the West, against a hardline judge who says Rouhani has gone too far and sold out the values of Iran’s Islamic revolution to its enemies. Rouhani, 68, who swept into office four years ago promising to open Iran to the world and give its citizens more freedom at home, faces an unexpectedly strong challenge from Ebrahim Raisi, a protege of supreme leader Ali Khamenei. Raisi has blamed Rouhani for mismanaging the economy and has traveled to poor areas holding rallies, pledging more welfare benefits and jobs. He is believed to have the backing of the powerful Revolutionary Guards security force, as well as the tacit support of Khamenei, whose powers outrank those of the elected president but who normally steers clear of day-to-day politics. The Guards and other hardliners hope that a win for Raisi, 56, will give them an opportunity to safeguard economic and political power they see as jeopardized by the lifting of sanctions and opening to foreign investment. During weeks of campaigning the two main candidates exchanged accusations of graft and brutality in unprecedentedly hostile television debates. Both deny the other’s accusations. Some 350,000 members of the security forces were deployed around the country to protect the election, state television reported. The interior ministry said at mid-day that it had no reports of electoral offences so far, state television reported. Rouhani has urged the Guards not to meddle in the vote, a warning that reflects the political tension. Suspicions that the Guards and the Basij militia under their control falsified voting results in favor of hardliner Mahmoud Ahmadinejad led to eight months of nationwide protests in 2009, which were violently suppressed. For conservatives, the election represents a chance to restore the values of the 1979 revolution, which requires elected officials to be subordinate to the Shi’ite Muslim clergy and supreme leader. In public, Khamenei has remained neutral, repeatedly calling for a high turnout. But Iranians in both political camps suspect he is in fact backing his protege Raisi -- not only for the presidency but potentially also as a possible successor to his own post of supreme leader, which the 77-year-old hardline cleric has held since 1989. Despite the removal of nuclear-related sanctions in 2016, lingering unilateral US sanctions that target Iran’s record on human rights and terrorism have kept foreign companies wary of investing in Iran, limiting the economic benefits so far. Two other conservative candidates are still officially in the race. If no candidate wins more than 50 percent of the vote, the top two, presumably Rouhani and Raisi, would face each other a second time in a run-off in a week. Ballot counting was expected to start at midnight and final results are expected within 24 hours of polls closing, TV reported. The elections are also for city and village councils.