|Iranian politicians have called for opposition leaders to be handed the death penalty following the protests [AFP]
Two people were killed at a banned opposition rally in Iran, a member of parliament has told the
Iranian Students' News Agency.
"At Monday's rally ... two people were martyred and many were wounded; one person was shot dead," Kazem Jalali said.
It was unclear how the second protester died.
So far, Iranian police have confirmed that one person was killed during clashes and blamed an outlawed group for shooting into the crowd.
"One person was martyred by Monafeghin [the People's Mujahedeen of Iran - PMOI] in the shooting at yesterday's events," Ahmad Reza Radan, deputy police chief of Iran, said on Tuesday, adding that nine security personnel were injured.
Earlier, the semi-official Fars news agency reported that a bystander had been shot dead and several wounded by protesters.
But the National Council of Resistance of Iran, which includes the PMOI, denied the allegations on Tuesday, saying "those in power crushed the demonstrators, firing live rounds and tear gas at them".
The Associated Press news agency had quoted witnesses saying that at least three protesters had been injured by bullets while dozens more were hospitalised after being beaten.
Dorsa Jabbari, Al Jazeera's correspondent in Tehran, confirmed reports that security forces used tear gas, pepper spray and batons against the protesters.
As with other foreign media, she was prohibited by government order to witness the demonstrations.
During Monday's protests, thousands of people descended on central Tehran in support of the uprisings across Arab nations.
But Iranian politicians have called for opposition leaders to be handed the death penalty following the protests, accusing them of fomenting unrest.
"Mehdi Karroubi and Mir Hossein Mousavi are corrupts on earth and should be tried," politicians were quoted as saying by the official Irna news agency.
Protesters burn a picture of the late Ayatollah Khomeini and Iran's supreme leader Ayatollah Seyyed Ali Hoseyni Khamenei. The demonstrators can be heard to chant "Mubarak, Ben Ali, now it's Seyyed Ali's turn."
The term "corrupt on earth", a charge which has been levelled at political dissidents in the past, carries the death penalty in the Islamic republic.
Gholamhossein Mohseni-Ejei, a judiciary spokesman, said: "Those who created public disorder on Monday will be confronted firmly and immediately."
Human-rights groups have criticised Iran's crackdown on protesters, while Western governments have voiced their support for the demonstration.
Amnesty International, the UK-based rights organisation, condemned authorities for making dozens of arrests, saying the crackdown was aimed at blocking the work of activists and stifling dissent.
"Iranians have a right to gather to peacefully express their support for the people of Egypt and Tunisia," Hassiba Hadj-Sahraoui, Amnesty International's Middle East and North Africa deputy director, said.
Catherine Ashton, the European Union's foreign policy chief, urged Iran to refrain from using force against protesters, while Hillary Clinton, the US secretary of state, backed the rights of people to protest.
"We wish the opposition and the brave people in the streets across cities in Iran the same opportunity that they saw their Egyptian counterparts seize in the last week," Clinton said.
An Iranian foreign ministry spokesman said comments from US officials were designed to distract from the changes going on in the Middle East.
Monday's marches were organised as a one-day event and it is unclear if further protests will take place later in the week.
A message posted on by the organisers of the demonstrations on the 25 Bahman Facebook site seemed to indicate that there might be more protests.
"The 25 Bahman group will try to announce the programme for of protests for tonight and tomorrow shortly," it read.
The current security clampdown is reminiscent of the one that crushed a wave of protests after the disputed re-election of Mahmoud Ahmadinejad, the Iranian president, in June 2009.
There was few mentions of Monday's demonstrations on state-run television stations or websites.