Thousands of Iranians took to the streets Wednesday to mark the 30th anniversary of the 1979 seizure of the US Embassy in Tehran, but the annual state-sponsored anti-American rally turned into another sign of the deep divisions persisting in this country. As pro-government demonstrators ritually chanted "Death to America!" outside the former US Embassy, opposition protesters used the occasion to vent their anger over a disputed presidential election in June and the harsh crackdown on subsequent protests. Converging on a square about half a mile from the former embassy, the opposition marchers denounced President Mahmoud Ahmadinejad with shouts of "Death to the dictator!" The rival demonstrations - and ensuing street clashes between protesters and security forces - illustrated the split that has come to define Iran three decades after Islamic revolutionaries overthrew the US-backed shah and branded America "the Great Satan." While Iran's ruling ayatollahs and government leaders maintain their entrenched distrust of and enmity toward the United States, the young people who form the bulk of Iran's population have no memory of those revolutionary days, and many opposition supporters favor a more open society and greater international engagement. The government has struggled to quell protests for five months, deploying security forces on the streets of Tehran and officially banning opposition demonstrations. Yet, on Wednesday, anti-government demonstrators openly defied the ban, even as police fired tear gas and warning shots. In video clips captured by cellphone cameras, helmeted police officers could be seen beating protesters, including women, with batons.