Iranian President Mahmoud Ahmadinejad has again called the Holocaust a lie by Western nations designed to create a pretext for the creation of the Jewish state of Israel.

Mr. Ahmadinejad made the comment Friday as tens of thousands of Iranians filled the streets of  the capital, Tehran, for an annual government-sponsored rally to express support for Palestinians and condemn Israel.

The Iranian president called the Holocaust a myth and an unproveable lie designed to promote support for Israel.

Opposition groups also took part in Friday's rally, despite a warning by security officials to stay away.  Opposition activists sought to take advantage of the large gatherings to protest the disputed re-election of President Mahmoud Ahmadinejad.

Security officers clashed with the opposition supporters and several protesters were detained.

Following Iran's disputed June 12 elections, rights groups said hundreds of people were detained in clashes with security forces during post-election, anti-government demonstrations.  Since then, authorities have held public trials of the accused and tried to marginalize moderate officials within the government.

Some information for this report was provided by AFP, AP and Reuters.