Teheran, 15 June-(ANA)-Iran's defeated moderate candidate Mir Hossein Mousavi has cancelled a big rally amid unrest over President Mahmoud Ahmadinejad's re-election.
The interior ministry had declared planned protests illegal.
Mr Mousavi wants election results annulled, alleging widespread fraud. Mr Ahmadinejad says the vote was fair.
Tens of thousands rallied in Tehran on Sunday to celebrate his victory.
Following two days of unrest over the weekend, the interior ministry said on Monday: "Some seditious elements had planned to hold a rally."
It added: "Any disrupter of public security would be dealt with according to the law."
Hours later, Mr Mousavi announced that the rally had been called off.
However a smaller demonstration has been taking place at TehranUniversity, at which Mr Mousavi's wife called for protests to continue.
A supporter of Mr Mousavi, Shahab Tabatabaei, told the Associated Press news agency the candidate had met Ayatollah Khamenei to press his call.
Sunday also saw clashes between the police and anti-Ahmadinejad protesters in several parts of Tehran for a second day.
Police hit protesters with batons and charged them on motorbikes.
Mousavi supporters cried "death to the dictator" into the evening. Scores of people are reported to have been arrested.
Mr Ahmadinejad dismissed the unrest as "passions after a soccer match".
More foreign powers are also expressing concern about the election.
In an interview on US television, Vice-President Joe Biden said: "It sure looks like the way they're suppressing speech, the way they're suppressing crowds, the way in which people are being treated, that there's some real doubt."
German Foreign Minister Frank-Walter Steinmeier said he had summoned the Iranian ambassador to explain the election.
"There are a lot of reports about electoral fraud," he said.
French Foreign Minister Bernard Kouchner said: "I am sorry that instead of openness there has been a somewhat brutal reaction."
But Mr Ahmadinejad was congratulated by the presidents of Iraq, Afghanistan and Venezuela. (ANA)