Tens of thousands of people were seen on Monday at Tehran's Enghelab Avenue marching all the way west to the prestigious Azadi (liberty) square, for a massive, peaceful rally to support the defeated presidential candidate Mir-Hossein Mousavi.

Supporters of Iran's former Prime Minister Mousavi hold a picture of Mousavi during a rally in Tehran, capital of Iran, June 15, 2009. Tens of thousands of people were seen on Monday at Tehran's Enghelab Avenue marching all the way west to the prestigious Azadi (liberty) square, for a massive rally to support the defeated presidential candidate Mir- Hossein Mousavi. [Stringer/Xinhua]

The participants, clad in green, or Mousavi's campaign signature, were carrying posters bearing the phrase of "New Greetings to the World", hand-written placards saying "where is my vote?", "we are not rioters", "this is not election, this is selection" and chanting "Allah-o-Akbar (God is the Greatest)."

Mousavi addressed his fervent supporters by a mobile loudspeaker saying that he was ready to take part in any new election.

Following the violent protests against the alleged "fraud" results of the country's presidential elections in the past two days, the backers of Mousavi were "staging a calm and peaceful demonstration," the local satellite Press TV reporter said.

Mehdi Karroubi, another defeated candidate, also defiant to the announcements released by both the Interior Ministry and the Police Chief, were seen along with Mousavi to join the mass rally that has been declared "illegal" by authorities, the report by Press TV said.

A supporter of Iran's former Prime Minister Mousavi makes a victory sign during a rally in Tehran, capital of Iran, June 15, 2009. [Xinhua]

Iran's Police Chief Esmail Ahmadi-Moghaddam warned on Monday that any illegal rally would be confronted in a legal way by the police.