Nov. 4 (Bloomberg) -- Iranian opposition supporters used state-sponsored rallies marking the 30th anniversary of the U.S. Embassy seizure to revive their protests over the re-election of President Mahmoud Ahmadinejad.

Protesters from the so-called green movement, shown by international broadcasters waving flags of that color, defied a post-election ban on opposition protests. They filled streets around Tehran University, chanting “death to the dictator,” according to the opposition Mowj Web site. Riot police fired shots into the air and tear gas to disperse the crowd. In nearby Haft-e-Tir Square, several people were beaten and others pushed into a van by the police, Mowj said.

The focus of today’s official gatherings is the annual demonstration outside the former embassy, where “death to America” has been the traditional chant. Roads leading to the building were blocked, Mowj said. State television showed a crowd of thousands at the site, many waving Iran’s flag and holding pictures of Ayatollah Ali Khamenei, supreme leader of the Shiite Muslim government that came to power in the 1979 revolution that ousted U.S.-backed Shah Mohammed Reza Pahlavi.

President Barack Obama said Iran has the choice to seek “greater opportunity,” according to a statement marking the anniversary of the embassy takeover, which he said had helped to put the U.S. and Iran “on a path of sustained suspicion, mistrust, and confrontation.” The U.S. cut diplomatic ties with Iran in 1980 in response to the seizure, in which 52 diplomats were held hostage for 444 days. Iran’s government has said the Nov. 4, 1979, event was a reaction to U.S. “arrogance.”

Mousavi, Karrubi

Iran’s police had sought to dissuade supporters of opposition leaders Mir Hossein Mousavi and Mehdi Karrubi, the main defeated candidates in the June 12 election, from using today’s occasion for rallies. “The police will act against any illegal gathering,” deputy police chief Ahmad Reza Radan warned earlier this week.

Streets protests have died down in recent months after a June outpouring in Tehran and major cities, which was prompted by allegations that Ahmadinejad’s victory was rigged. He rejects the claim. Sporadic demonstrations have since been held by the opposition, including on Sept. 18, during the state-sponsored national Quds Day, which the government organizes annually in support of the Palestinians.

Obama’s Message

In his message, Obama called on Iranian leaders to let go of the past.

“We have heard for 30 years what the Iranian government is against; the question, now, is what kind of future it is for,” Obama said in the statement released by the White House. “It is time for the Iranian government to decide whether it wants to focus on the past, or whether it will make the choices that will open the door to greater opportunity, prosperity and justice for its people.”

The U.S., which has said it suspects Iran is trying to make a nuclear bomb, is working with France, the U.K., Germany, Russia and China to persuade Iran to suspend the enrichment of uranium to prove its atomic program is peaceful. The government in Tehran insists its nuclear program is intended only for civilian purposes such as electricity generation.

To contact the reporter on this story: Ladane Nasseri in Beirut at lnasseri@bloomberg.net.

Last Updated: November 4, 2009 05:54 EST