Today, 20 February 2011, an eyewitness student activist told the International Campaign for Human Rights in Iran that tens-of-thousands of protestors in Tehran marching in the rain and security forces were out in significantly large numbers. On occasion, they used tear gas and arrested demonstrators. The student activist witnessed three arrests. He said: “I started at Vali Asr Square. At 4pm people were starting to gather and went down to Vali Asr Crossing. There was a dense crowd there walking towards Enghelab Square on the sidewalks of Enghelab and Azadi street. I’d say two hundred thousands. As many people as [where out] on 25 Bahman (14 February) but the difference was that they were scattered across two axes, Enghelab and Azadi, and Vali Asr. Demonstrators were mostly walking in silence, except when attacked by the security forces. People seemed to prefer demonstrating in silence in order to reduce the level of tension and violence. But there were also slogans, mostly Allah-o Akbar and also some against the Supreme Leader. But people rarely talked, it was dangerous to talk, and gather attention. “There were many many security forces. I don’t know, maybe 50,000 on Enghelab and Azadi alone. Many of them were on other streets leading to the main street. All along the way they were present but not violent, most of them Basijis, [both] uniformed and plainclothes. Many with bikes. [There were] also riot police [but] in fewer numbers. The whole city was virtually turned into a military fort. I think [the security forces] were… taking pictures and videos. I had never seen this number of security forces on the streets of Tehran even on the worst days of demonstrations maybe only equivalent to 30 Khordad ‘88 (20 June 2009). “I didn’t see any significant violence but somewhere along the way I smelled the sting of tear gas. It [sounded] as there was one [gun] shot, [as we approached] Enghelab Square. “It seems that the security forces were given specific orders not to engage with the demonstrators unless they started shouting slogans. People were calm and smiling but from time and time again security forces selected one person among the crowd and arrested them, sometimes [using] batons, but not very violently. I witnessed three arrests. “The riot police had some new [type of] gun, i didn’t see them using it but it seemed to be for shooting rubber bullets, different from paint balls. Their restraint was unprecedented, unexpected and surprising. It seems the government wanted the situation to appear normal, not to make people more angry than they already are.”

Source: http://www.iranhumanrights.org/2011/02/an-eye-witness-the-security-forces-were-out-in-significant-numbers/