Tehran  - Iran's supreme leader Ayatollah Ali Khamenei is expected to speak out for the first time at Friday's prayers, following days of opposition protests against alleged manipulation in last week's presidential election.

Khamenei, who is said to back the re-election of President Mahmoud Ahmadinejad, which sparked the protests, is expected to address the situation. As Iran's supreme leader, Khamenei has a final say on all political decisions in the Islamic republic.

No protest rallies are planned Friday, but another mass protest was announced for Saturday. On Thursday, hundreds of thousands of supporters of opposition leader Mir-Hossein Moussavi took to the streets again, demanding a re-run of the elections.

Meanwhile Iran's Guardian Council, which is in charge of approving the election process, invited Moussavi and two other presidential candidates, Mehdi Karroubi and Mohsen Rezai, to participate in a review of the election results on Saturday.

The candidates claimed 646 irregularities in the June 12 polls, where Ahmadinejad won a landslide 63-per cent victory, according to official results.

Protestors on Thursday wore black to mourn those killed in the demonstrations, and green, the colour chosen by Moussavi as a symbol for change, in what probably are the biggest mass protests in the Islamic republic's 30-year history.

According to the opposition People's Mujaheddin Organisation of Iran, a group which was recently removed from an European Union terrorism blacklist, 43 people have been killed in the protests, 30 of them in Tehran.

There is no independent confirmation of those figures, previous reports spoke of at least eight people killed in clashes with security forces. (dpa)