New Year's Eve Clashes in Streets of Iran Protester calls crackdown the "last efforts of a dying state in denial."

LONDON, Dec. 31, 2009 -- Pro-government militia called Basij spread out through the streets of Tehran on New Year's Eve today to discourage planned protests by opponents of the regime, clashing at times with peaceful marchers.

"These are the last efforts of a dying state in denial," one protester told ABC News after he had seen the city filled with security forces.

Haft-e-tir Square, a downtown Tehran shopping and transport hub, was full of people who gathered in discreet protest early in the day. Surrounded by government militia, the protesters were somewhat muted but the situation was tense, an eyewitness told ABC News.

A pro-green Web site, Jaras, reported that the situation had escalated and police had fired tear gas.

"Supporters of opposition leader (Mirhossein) Mousavi clashed with police in Haft-e-Tir Square and police fired two rounds of tear gas to disperse the protesters," the Jaras web site said.

A similar report on Twitter said the protesters had been attacked by security forces and the demonstrators retreated to back alleys.

This could not be independently verified as media access to these protests and others has been banned.

There are also unconfirmed reports that several metro stations have been shut down to hinder the protesters' movement.

Police helicopters circled the city all day and on-line reports claimed that soldiers were being brought to the city from surrounding areas prompting fears that Tehran could soon be put under the control of the Revolutionary Guard.

Officials denied the report that troops, which have not previously been used for crowd control, had been called in.

Due to the regime's clampdown on the media it remains difficult to sort through the conflicting claims by the government and the Green Movement as protesters have been called.

The general mood of the city has been one of tension in recent weeks, according to reports leaking of Iran on the Web and by Twitter. There has been an increase in security forces, both in uniform and in plain clothes, stopping people to check their IDs.

Women are stopped and their purses checked and vehicles with two or three young adults in them are frequently stopped and the occupants told to get out to be frisked, according to Twitter accounts from Tehran.

Iran Protesters Accuse Government of Disinformation

Government opponents also say that the state media is deliberately putting out misinformation.

Iran's official news agency carried a report Wednesday that the leaders of the Green Movement, Mir Hussein Mousavi and Mahdi Karoubi had fled Tehran, fearing for their safety.

"Two of those who played a major role in igniting tension in Iran following the vote, fled Tehran and went to a northern province because they were scared of people, who demanded their punishment," IRNA reported, without naming the two.

The report was immediately denied by Karoubi's son. "My father and Mr. Mousavi are in Tehran and IRNA's report is baseless. They are still pursuing the people's demands," Hossein Karoubi told moderate Parlemannews.

ABC News sources also indicated that both leaders never left Tehran and opponents of the government are dismissing this report as state propaganda designed to denigrate the two who are still contesting President Ahmadinejad's legitimacy as president after this summer's disputed elections.

An earlier rumor that Mousavi's wife, Zahra Rahnavard, had been arrested was also dismissed.

"This is misinformation by the government. They are testing the reaction of the people and they are going to make people afraid," Mohsen Makhmalbaf, Mousavi's unofficial spokesman told ABC News.

Hardline leaders have been calling this week for opposition leaders to be punished for fomenting unrest in Iran, which has been rocked by political turmoil since the June election.

Today the state prosecutor Gholam Hossein Mohseni Ejehei said the leaders may face charges of "supporting apostates," or those who go against God. His comments were published in the state-owned Iran newspaper.

The police posted on their Web site about 100 pictures of opposition protesters involved in Sunday's demonstrations, asking the public to help identify and report them on suspicion of "damaging public property and insulting sanctities."

Since Sunday's bloody clashes which left eight protesters dead, 500 people have been arrested, according to Iran's police Chief Gen. Ismail Ahmadi Moghaddam. This number could be higher because hardline Basij militiamen and intelligence agents may have apprehended more people on their own, Moghaddam told IRNA.

The pro-green web site Jaras says that as many as 1,510 people are being held and according to HRNA (Human Rights Activist News Agency) the notorious Evin prison is overflowing.

"According to reports from a human rights group in Iran, the massive number of arrests in the past three days forced Evin prison authorities to build a temporary detention center inside the prison." HRNA reported.

Photographs published on-line Tuesday purportedly showed people gathered outside the prison hoping for news of relatives inside.

Iranian Regime's New Tactics

Among those arrested in the last few days was the sister of Iranian Nobel Peace Prize winner Shirin Ebadi. Makhmalbaf views this is part of the new intimidation tactics being used by the regime. "They arrested the sister of Shirin Ebadi to put her under pressure. This is the style of the Mafia," he said.

"They always change their tactic and strategy. On Ashura they were killing people and targeting people," referring to the religious holiday earlier this week. "This is new, targeting. They are telling people we can kill you."

Makhmalbaf believes the government deliberately targeted Mousavi's nephew, a claim the police have denied.

They are not, however, shying away from threatening violence against the protesters. "The days of tolerance are over and the police will have a severe encounter with riot makers," Moghaddam warned Tuesday.

But such threats are not silencing members of the Green Movement as they continue to call for peaceful protests. "Go help your brothers!"one pro-green blogger encouraged.

Reuters contributed to this report