Anti-U.S. and anti-government protesters crowded Tehran streets Wednesday, the 30th anniversary of Iranian students storming the U.S. Embassy.

Anti-government protesters clashed with security forces in the republic's capital, where witnesses told CNN security forces pumped tear gas into crowds and fired shots into the air to disperse the demonstrators.

Traditionally, Nov. 4, a national holiday in Iran, is marked by anti-U.S. sentiment in commemoration of the U.S. Embassy takeover by radical students and the holding of 53 embassy personnel hostage for 444 days.

"The Americans are scared of religious democracy in our country more than anything else," lawmaker Gholam-Ali Haddad-Adel said in an official rally marking the anniversary. "This is because Iran's religious democracy could turn into a role model in other countries."

Anti-government demonstrators sought to turn the anniversary rally into a protest against the disputed June 30 election in which President Mahmoud Ahmadinejad was declared the winner, the New York Times reported.

Government opposition leaders ignored threats of arrest for chanting anything other than "Death to America," the Times reported. Government leaders also said no rallies would be permitted except state-sanctioned ones outside the former U.S. Embassy.