Claiming to be from Sunday, this Youtube video shows crowds in Shiraz scattering as they're charged by men on motorcycles.
There are reports of renewed anti-government protests in Iran, with demonstrators taking to the streets in several cities across the country.
There have also been clashes between protesters and security forces, posts on social networking sites such as Facebook and Twitter said on Sunday. There were also reports of one protester being shot dead in Tehran, a story denied by government official in state media.
|Faezeh Rafsanjani, detained in a blacked-out van used by secuirty forces ro round up protesters [IRNA]
The official IRNA reported that Faezeh Rafsanjani, the daughter of ex-president, Akbar Hashemi Rafsanjani, has been among those arrested for particiapting in the protest. Fars news agency reported that she was released shortly thereafter.
Protesters have apparently thronged Tehran's Vali-Asr and Enghelab squares. Similar demonstrations are being reported in Shiraz and Isfahan.
Reformist news sites said security forces were responding to the protests in some measure.
Rahesabz.net reported that a number of plainclothes Basij security forces, some on motorcycle, had arrived at the protest in Shiraz, carrying the flag of the Islamic republic. They also blocked the entrance to some streets.
A page on Facebook used to organise the protests also carried a post saying that security forces were beating protesters with batons and chains in the northern city of Rasht.
Citing witnesses inside the country, sources told Al Jazeera that plainclothes security forces were rounding up and taking away groups of protesters near Sharif University in Tehran, near Azadi Square.
The page also quoted witnesses as saying that tear gas had been used against protesters in Tehran, and the BBC Persian website said gunshots had been heard in the Abbas Abad area, west of Vali-Asr street.
Marching in silence
In e-mailed accounts of protests sent to Al Jazeera, two demonstrators said that the crowd was roughly the same size as the February 14 protests. They described scenes of heavy tension and mass security presence, some of whom were recording protesters.
One said that Tehran seemed to have "been turned into a military fort" and added that he was able to use his mobile phone to contact friends from time to time, "but only when not in danger of being caught."
A video from Iran Reporter, purportedly from Sunday, shows a man being forced into a security van
He said that while he saw some instances of people being arrested or beaten with batons that, "It seems that the security forces were given specific orders not to engage with the demonstrators unless they start shouting slogans."
People seemed to prefer demonstrating in silence in order to reduce the level of tension and violence," he wrote, "But there were also slogans ... but people rarely talked - it was dangerous to talk."
Another account, also from Tehran, indicated that security forces tended to confront protesters when they were chanting.
"There was tear gas involved if people (usually in groups of 100-150) chanted 'Down with the dictator,'" wrote the second eyewitness, who also said he'd witnessed arrests - one at Vali Asr Square and another of a girl on a bus, who was filming the protest.
"There weren't that many chanting going on today ... mostly people were silent."
Meanwhile, Kaleme.com - which belongs to Mir Hossein Mousavi, who, along with fellow opposition leader Mehdi Karroubi remains under house arrest - reported that plainclothes security forces were speeding through crowds of protesters in Tehran in an attempt to cause panic and to disperse.
Al Jazeera cannot independently confirm the reports.
State news agency Fars, however, said that Tehran is in a state of "total calm".
The International Campaign for Human Rights in Iran said that eyewitnesses it has spoken to confirm the use of live ammunition and teargas by security forces in Iran. An article posted on the group's site also said that "large scale" protests have been taking place in various cities and that they're continuing to grow in size.
The Iranian government has tried to dissuade protesters from taking to the streets via state media, first by saying that members of the banned group People's Mujahedeen of Iran (MKO) were planning on killing people at the protests, and then by saying that live ammunition would be used against protesters who defied its orders.
The Fars news agency also published an interview with lawmaker Seyyed Mohammad Javad Aabtehi, in which he said that not only should people refrain from participating in any kind of gathering, but that they should even avoid observing the protests.
The Human Rights House of Iran (RAHANA) reported that prior to the start of the protests on Sunday, there were also numerous reports of uniformed and plainclothes security forces in several key gathering points in the capital and that there were "several cars in Azadi street which are believed to be for detaining the citizens".
The rights group also reports that at least 50 people had been detained in Shiraz.
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