Supporters of defeated presidential candidate Mir-Hossein Mousavi have gathered in central Tehran for a fifth day of protests against election results.

Crowds of supporters marching silently from nearby streets towards Haft-e-Tir square in downtown Tehran on Wednesday afternoon in a demonstration that started at 2:00 p.m. local time (0930 GMT).

Reports say Mousavi did not attend the march. The crowds headed towards the Vali Asr square, where Ahmadinejad's supporters had gathered on Sunday and Tuesday.

Friday's presidential election, which saw incumbent Iranian President Mahmoud re-elected for a second term in office, has caused mass rallies by hundreds of thousands of Mousavi's supporters who reject the election as fraudulent.

Some of the demonstrations have tuned violent resulting in the deaths of at least eight people in the Iranian capital.

In a statement released on Wednesday, Mousavi asked the Iranian nation to wear black on Thursday to show solidarity with the families of those who have lost their lives since the clashes erupted. He added that he would take part in Thursday's rallies.

While Mousavi backs the right of his supporters to peaceful protests, the candidate has asked his supporters to keep calm, remain vigilant and avoid falling into 'traps' set by miscreants who seek to flame violence.

Iran's last prime minister has called on the Guardian Council, the body that supervises the electoral process, to nullify the Friday vote and hold the election anew.

Mousavi, who according to the Interior Ministry has lost to Ahmadinejad even in the East-Azerbaijan province where he hails from, cried foul and described the election as a 'charade' -- a charge the president and his interior minister have denied.

He outlines the Interior Ministry's unprecedented speed in announcing the winner, its unusual delay in releasing the detailed list of the ballot and the absence of his monitors in some voting stations, as proof for his claim.

AKM/MMN