Large crowds of Iranians have demonstrated outside the former U.S. Embassy in Tehran to mark the anniversary of the 1979 takeover. Iranian media reports say the hard-line protesters were holding anti-U.S. placards and shouting "Death to America!"
Some stomped upon images of U.S. President Barack Obama and U.S. flags while others burned an American flag. Many were carrying yellow flags that said "Death to America."
Similar rallies were held in other Iranian cities, including Shiraz and Rasht.
The rally is an annual event, but observers say this year it has greater significance because hard-liners are expressing opposition to attempts by new Iranian President Hassan Rohani to ease tensions with the United States.
A telephone conversation between Rohani and Obama in September was met with approval by many Iranians but with suspicion by hard-line Iranian groups who called it premature.
Student activists stormed the U.S. Embassy in November 1979 following the Islamic Revolution.
A total of 52 American hostages were held for 444 days.
This year's anniversary came amid calls in Iran by moderates and others to drop the "Death to America" chants that are a regular part of state-organized events, including the annual demonstrations to mark the embassy takeover.
Hard-liners, including commanders of the Islamic Revolutionary Guards Corps (IRGC), have rejected those calls and said that the habitual refrain of "Death to America" will remain eternal.
Rohani did not attend the November 4 demonstrations. Government officials from the Health and Education ministries took part in the rallies, according to reports by state media.
Among the main speakers at the rally were former senior nuclear negotiator and defeated presidential candidate, hard-liner Said Jalili, who said the capture of the U.S. Embassy, called "the nest of spies" by some officials, showed that the revolution was on the right path.
Jalili defended the "Death to America" slogan as the slogan of the most "thoughtful and honest" Iranians and added the slogan was not directed against the American people but against its government officials.
He also said that Iranians monolithically support the clerical establishment, the government, and the team in charge of nuclear negotiations.
In a speech on November 2, Iranian Supreme Leader Ali Khamenei expressed support for the country's nuclear negotiators, apparently in an attempt to chide hard-liners who have been critical of Rohani's efforts to find a solution to the crisis over Iran's nuclear activities.
Khamenei said Iranian negotiators are not "compromisers."
"They have a difficult mission and no one must weaken an official who is busy with work," said Khamenei.
The Iranian leader praised students who stormed the U.S. Embassy 34 years ago.
Hard-liners unveiled two new "Death to America" songs on November 3.
The songs were performed at the former U.S. Embassy in Tehran.
With reporting by AP, dpa, and Reuters