Supporters of the main election challenger to Mahmoud Ahmadinejad clashed with police and set up barricades of burning tires Saturday as authorities declared the hard-line president was re-elected in a landslide. Opponents responded with the most serious unrest in the capital in a decade and charges that the result was the work of a «dictatorship.», AP reported. Iran's supreme leader, Ayatollah Ali Khamenei, closed the door on any chance he could use his limitless powers to intervene in the disputes from Friday's election. In a message on state TV, he urged the nation to unite behind Ahmadinejad, calling the result a «divine assessment.» But Ahmadinejad's main challenger, Mir Hossein Mousavi, has rejected the result as rigged and urged his supporters to resist a government of «lies and dictatorship.» The clashes in central Tehran were the more serious disturbances in the capital since student-led protests in 1999 and showed the potential for the showdown over the vote to spill over into further violence and challenges to the Islamic establishment. Several hundred demonstrators _ many wearing the trademark green colors of Mousavi's campaign _ chanted «the government lied to the people» and gathered near the Interior Ministry as the final count was announced. It gave 62.6 percent of the vote to Ahmadinejad and 33.75 to Mousavi, who served as prime minister in the 1980s and has become the hero of a youth-driven movement seeking greater liberties and a gentler face for Iran abroad. The turnout was a record 85 percent of Iran's 46.2 million eligible voters. Two other candidates received only a fraction of the vote.