Iran’s Supreme Leader has issued a stern warning that protests against the country’s disputed presidential election results must end. In his first public remarks after days of demonstrations, Ayatollah Khamenei said the outcome must be decided at the ballot box, not on the street. He said political leaders would be blamed for any violence. Demonstrators calling for a new election earlier vowed to stage fresh protests on Saturday. Addressing thousands of people at Tehran University, the ayatollah voiced support for President Mahmoud Ahmadinejad, saying the president’s views on foreign affairs and social issues were close to his. Responding to allegations of electoral fraud, the ayatollah insisted the Islamic Republic would not cheat.