TEHRAN - Iranian opposition leader Mirhossein Mousavi appeared to urge his supporters on Saturday to take part in rallies on November 4 marking the 30th anniversary of the seizure of the U.S. embassy in Tehran.

If they gather in the streets on Wednesday, there may be clashes with police and government backers, as happened during annual demonstrations in Iran in support of the Palestinians on September 18.

In a statement posted on a reformist website, Mousavi said he would press ahead with his efforts for political change in Iran following its disputed election in June, which he says was rigged in favor of hardline President Mahmoud Ahmadinejad.

Referring to the Iranian date of the seizing of the U.S. embassy in 1979, Mousavi said on his kaleme.com website: The 13th of Aban is a ... rendezvous so we would remember anew that among us it is the people who are the leaders.

He said: Our green path is a rational one and a bearer of good news since it shows that we will stand firm on our demands. Green was the color of Mousavi's election campaign.

Apart from sporadic incidents, the streets of Tehran have returned to normal since the poll sparked Iran's worst street unrest since the Islamic revolution three decades ago.

Anti-Western rallies usually take place outside the old U.S. embassy to mark the day in 1979 when radical students scaled its walls and took 52 Americans hostage, holding them for 444 days. Washington cut diplomatic ties with Tehran in 1980.

Some reformist websites have called on people to gather outside the Russian embassy instead, in an apparent protest at Moscow's swift recognition of Ahmadinejad's election victory.

Iranian security officials have ordered the opposition not to hold demonstrations on that day.

PEOPLE'S OPPONENTS

The elite Revolutionary Guards and an allied Islamic militia quelled the huge opposition protests that erupted in the days after the June 12 vote and thousands of people were arrested.

Most of the detainees have since been released, but more than 100 senior reformers, activists, journalists and others have been put on trial, accused of fomenting street unrest. The opposition has denounced the court sessions as show trials.

Several of the accused have received jail sentences and three have been sentenced to death, according to Iranian media. Under Iranian law, the verdicts can be appealed.

The authorities have portrayed the post-election street demonstrations as a foreign-backed bid to undermine the Islamic Republic. They reject charges of vote rigging, describing the election as the country's healthiest for three decades.

Supreme Leader Ayatollah Ali Khamenei, Iran's top authority, said earlier this week that it was a crime to question the election and stressed the big turnout, and hardliners have called for Mousavi to be prosecuted.

Ahmadinejad has consolidated his position in recent months, winning parliament's backing for his government as well as for an economic reform plan. But Mousavi and pro-reform cleric Mehdi Karoubi have continued to voice defiance.

Sooner or later ... the people's opponents will be leaving the scene. But does it mean a devastated country will have to remain for the nation on that day? Mousavi said on Saturday.
The opposition says more than 70 people were killed in the post-election violence. Officials say the death toll was half that and that members of the security forces were among the victims.

(Editing by Tim Pearce)