Iran's Supreme Leader Ayatollah Ali Khamenei has attacked "enemies" who question the result of a presidential vote that has sparked the biggest street protests in the Islamic Republic's history.
"Today the Iranian nation needs calm," Mr Khamenei said in his first address to the nation since the upheaval began.
He said Iran's enemies were targeting the legitimacy of the Islamic establishment by disputing the outcome of the election, officially won by the incumbent, Mahmoud Ahmadinejad.
Speaking during Friday prayers at Tehran University, he described the election as a great display of democracy, with more than 40 million people - 85% of eligible voters - taking part, the best result since 1979.
He praised the people of Iran for their participation and cooperation and said the high turnout showed the trust they have in the state.
Tens of thousands gathered for sermon
Tens of thousands gathered in and around the university to hear the prayer sermon. People chanting slogans and holding posters of Mr Khamenei, Mr Ahmadinejad and Ayatollah Ruhollah Khomenei, the father of the 1979 revolution, packed the streets around.
Some in the crowd were draped in Iranian flags. Others held placards with anti-Western slogans.
"Don't let the history of Iran be written with the pen of foreigners," one flyer said, reflecting official Iranian anger at international criticism of the post-election violence.
Warning for protest leaders
The leader issued a stern warning against continuing the massive, if peaceful, street protests they have staged since the election results were declared.
He said they were an illegal and wrong-headed attempt to pressure officials into giving in to their demands, that the protests provided cover for provocateurs to stir violence, and that the political leaders concerned would be responsible for the consequences if they did not stop.