TEHRAN – President Mahmoud Ahmadinejad said on Tuesday those behind anti-government protests in Iran will fail, as furious lawmakers demanded the execution of opposition chiefs who had called for the rallies.

US President Barack Obama, in one of his most direct reactions to Monday's events in Iran, offered encouragement to protesters, saying he hoped they would have the "courage" to keep expressing their "yearning for greater freedoms."

In a live interview on state television, Ahmadinejad said: "It is evident and clear that the Iranian nation has enemies because it is a country which wants to shine and achieve its peak and wants to change relations (between countries) in the world.

"Of course there is a lot of animosity, even against the government. But they (protest planners) will not achieve their goals," he replied when about Monday's demonstrations in the capital.

Two people were killed in the protests and several were wounded, including nine members of security forces, officials say, as riot-police fired tear gas and paintballs at demonstrators.

Thousands of anti-government supporters chanted anti-Ahmadinejad slogans under the pretext of holding a rally in support of Arab uprisings.

The rallies turned into protests reminiscent of June 2009 demonstrations after the disputed re-election of Ahmadinejad, with clashes erupting between protesters and riot-police, notably in Tehran's Azadi Square (Freedom Square).

Protesters and their leaders Mir Hossein Mousavi and Mehdi Karroubi, who planned Monday's rally, remain steadfast in rejecting Ahmadinejad's presidency.

The latest unrest triggered fury in Iran's conservative-dominated parliament, with lawmakers demanding that Mousavi and Karroubi be executed.

Mohammad Khatami, a former reformist president, also came under fire from conservatives for openly backing the opposition movement since the disputed presidential election.

"Mousavi and Karroubi should be executed! Death to Mousavi, Karroubi and Khatami!" lawmakers shouted in the house, state news agency IRNA reported.

They said the United States, Britain and Israel had orchestrated the protests through the opposition leaders, who, according to parliament speaker Ali Larijani, were being "misled" by Iran's arch-foes.

"The parliament condemns the Zionists, American, anti-revolutionary and anti-national action of the misled seditionists," a visibly angry Larijani told the parliament.

"How did the gentlemen (Mousavi and Karroubi) ... fall into the orchestrated trap of America?"

"Should they not have been cautious given the support, pleasure and joy of America and Israel as well as monarchists and Monafeghin?" Larijani added, referring to the outlawed People's Mujahedeen of Iran (PMOI).

He urged that a committee be formed to investigate and "confront" the opposition movement.

A pro-regime group gathered later on Tuesday outside Karroubi's house and chanted slogans against him, the cleric's website reported.

Fars news agency reported that some MPs and regime supporters also hanged and burned an effigy of Mousavi outside the Tehran prosecutor's office.

Obama defended the protesters and criticised the Iranian authorities, saying that unlike Egypt, Iran's response to protests has been "to shoot people and beat people and arrest people."

"And, you know, my hope and expectation is that we're going to continue to see the people of Iran have the courage to be able to express their yearning for greater freedoms and a more representative government," Obama said.

An unfazed Ahmadinejad criticised those who planned the protests.

"They want to dampen the brilliance of the Iranian nation. But it is a shining sun... they want to throw dirt at the sun," he said, referring to both opposition leaders and the West.

"But it (the dirt) falls back in their faces. I don't want to talk about ignorant people. I address those who design and plan these things. They are the people who will see the dirt fall on their faces."

Canada's Foreign Minister Lawrence Cannon backed Obama in accusing Iran of hypocrisy for cracking down on protesters while calling for democracy in Egypt.

"The hypocrisy of Iranian authorities' calls for democracy in Egypt and suppression of the same demands in Iran is deeply disturbing," he said.