The country's foreign minister disputed allegations of ballot irregularities in Iran's disputed presidential election, and the parliamentary speaker implied the nation's election authorities had sided with one candidate.

Amateur video showed large crowds marching down a major Tehran thoroughfare shouting, "Don't be afraid, we're together!" and "Death to dictator!" The person who shot the video said it was taken Sunday, but CNN could not immediately verify that the protest had taken place.

Eyewitnesses reported a protest also took place at Southern Tehran's Azad University, where final exams were postponed after about 200 students refused to take them.

Thousands of riot police and members of the Basij militia lined the streets of the city, according to eyewitnesses. Many shops were closed, and shopkeepers who were open said they planned to close early Sunday. However, no tanks were seen on the city's streets. Traffic was light.

Police have not been given permission to use firearms in confronting protesters, Tehran Police Chief Azizollah Rajabpour told Iran's semi-official Mehr news agency. Police have not used firearms on the public, he said.

Allegations to the contrary are false and "spread by those who want to muddy the waters," the agency reported.

Protesters dispute the results of the June 12 presidential elections.

News coverage in Iran has been limited by government restrictions on international journalists. On Sunday, the BBC said Iran had expelled Jon Leyne, the British network's permanent correspondent in Tehran. And Al-Arabiya, a Dubai-based Arab satellite network, said its Tehran bureau was ordered closed.

However, the protests appeared mostly peaceful, in stark contrast to Saturday's bloodshed. Hospital sources said 19 people were killed Saturday in clashes between protesters and police. Unconfirmed reports put the death toll as high as 150.

Government-funded Press TV confirmed 13 fatalities Saturday, saying the deaths resulted from police clashes with "terrorist groups" in Tehran. But the station did not say whether all the deaths took place Saturday or spanned the length of the weeklong protests.

Press TV also reported Sunday that five relatives of former President Ali Akhar Hashemi Rafsanjani were arrested for "alleged involvement in post-election incidents ... taking part in unauthorized protests in central Tehran ... they are accused of provoking riots."

All but Faezeh Rafsanjani, the former president's daughter, were later released, Press TV said. The woman's brother said she was arrested while taking part in a protest.