Iran's Mousavi defies crackdown
Mir Hossein Mousavi has not been seen in public for days
Iran protest leader Mir Hossein Mousavi says he holds those behind alleged "rigged" elections responsible for bloodshed during recent protests.
In a defiant statement on his website, he called for future protests to be in a way which would not "create tension."
He complained of "complete" restrictions on his access to people and a crackdown on his media group.
A BBC correspondent in Tehran says the statement is a direct challenge to Iran Supreme Leader Ayatollah Khamenei.
In another development on Thursday, Iranian state media said that eight members of the pro-government Basij militia had been killed and dozens more wounded in the protests.
The eight deaths were in addition to 17 other people whose deaths have already been reported.
The figures cannot be verified due to severe reporting restrictions inside Iran.
"I won't refrain from securing the rights of the Iranian people... because of personal interests and the fear of threats," Mr Mousavi said on the website of his newspaper, Kalameh.
Those who violated the election process "stood beside the main instigators of the recent riots and shed people's blood on the ground", Mr Mousavi said, pledging to show how they were involved.
Mr Mousavi, a former prime minister, spoke of the "recent pressures on me" that are "aimed at making me change my position regarding the annulment of the election".
He described the clampdowns he and his staff were facing.
"My access to people is completely restricted. Our two websites have many problems and Kalameh Sabz newspaper has been closed down and its editorial members have been arrested," said Mr Mousavi, who has not been seen in public for days.
"These by no means contribute to improving the national atmosphere and will lead us towards a more violent atmosphere," he added.
Day of mourning
Opposition leaders had called for a day of mourning on Thursday, but some reports say it has been cancelled.
Separately, nearly two thirds of MPs appear to have stayed away from President Mahmoud Ahmadinejad's election victory party.
All 290 MPs were invited to attend the party, Iran's press reports, but only 105 turned up. An earlier BBC report wrongly reported that 105 did not attend.
One of those who reportedly failed to turn up was Parliament Speaker Ali Larijani, a high-profile figure who shares some of Mr Ahmadinejad's hardline views but has been critical of some aspects of the government's handling of the protests.
About 50 MPs are reformist and would not have been expected to attend the victory party.
12 June Presidential election saw incumbent Mahmoud Ahmadinejad re-elected with 63% of vote
Main challenger Mir Hossein Mousavi called for result to be annulled on grounds of electoral fraud
Street protests saw at least 17 people killed and foreign media restricted
Q&A: Election aftermath
How Iran is ruled
Who's who in Iran
Iran: Send your questions
But the high number of MPs who stayed away is another indication that the disputed election has split the nation, says the BBC's Jeremy Bowen in Tehran.
President Ahmadinejad on Thursday criticised US President Barack Obama for his condemnation earlier this week of the violence in Iran.
"Our question is why he fell into this trap and said things that previously [former US President George W] Bush used to say," he was quoted by the semi-official Fars news agency as saying.
The Guardian Council, which supervises elections, has already said it will not re-run the election.
Ayatollah Khamenei reiterated on Wednesday that he would "not yield" over the election result.
Hundreds of opposition protesters and activists are believed to have been taken into custody and at least 17 protesters have died in the unrest since the election.
The Iranian government has set up special courts to deal with those arrested and has threatened harsh sentences.
Mr Mousavi's website reported on Thursday that 70 academics who visited the opposition leader on Wednesday had been arrested. It was not clear where they had been taken.
BBC's Jeremy Bowen
Wednesday's street protest was smaller than on previous days, as an increasingly heavy security presence took effect.
But there were reports of riot police firing tear gas, shooting in the air and beating demonstrators with batons.
Severe reporting restrictions imposed on foreign media in Iran mean the BBC cannot verify the reports.
Tehran has blamed foreign governments for inspiring the protests, but some Western countries are continuing to criticise its handling of the crisis.
"We stand beside you," said German Chancellor Angela Merkel, referring to "all in Iran who seek to demonstrate peacefully".
UK Foreign Secretary David Miliband told the BBC there is a "crisis of credibility between the Iranian government and their own people".
The Italian government said it hoped Thursday's meeting of Group of Eight foreign ministers would send a "tough" message to Tehran