Iranian opposition leaders are reported to have come under attack and their supporters have clashed with security forces, as Iran marks the anniversary of the 1979 Islamic Revolution.
The incidents came as tens of thousands of government supporters marched in the streets of Tehran and other cities to mark the day.
The most important holiday of the Islamic establishment, the anniversary of the 1979 revolution is being celebrated amid the crisis over last year's reelection of Iran’s President Mahmud Ahmadinejad, which the opposition believes was the result of fraud.
In a defiant speech in Tehran to mark the day, Ahmadinejad announced that the Islamic republic has produced its first highly enriched uranium just two days after beginning the process. He proclaimed that Iran was now a "nuclear state."
"I would like to say to you that the day before yesterday, the enrichment of [nuclear] fuel at 20 percent started," he said. "I would like to notify you and announce with a loud voice that, thank God, our chief nuclear negotiator announced that the production of fuel at 20 percent started under the watchful eyes of our scientists."Sporadic Clashes
Around the time Ahmadinejad spoke, sporadic clashes were reported between pro-government forces and opposition supporters in several locations in central and northwestern Tehran.
One protester who had just returned from Sadeghiyeh Square told RFE/RL that security forces would disperse even a crowd of 10 people. WATCH: Demonstrators escape a cloud of tear gas fired by security forces.
Another eyewitness in Tehran told Radio Farda that government forces were cracking down on the protesters.
“A few times, I heard tear-gas shells being fired. I saw [pro-government] forces beating up people with police baton and chains," he said. "I saw people who were injured...However, I didn’t see or didn’t hear from others that anyone was injured by gunshot.”
Another eyewitness said he saw security forces beating opposition supporters.
"I saw that they randomly pulled out a young man in Sadeghiyeh Square and started to beat him very severely," he said. "I heard shooting at the Ashrafi Esfahani highway. When I was passing Hakim Street and the nearby bridge, I saw that the area was full of people. Cars were honking. Green Movement supporters have been showing themselves."
Female students wave national flags during today's ceremonies in Tehran.
Somewhere nearby, opposition leader Mehdi Karrubi and his supporters were reported to have come under attack by security forces.
Karrubi’s son, Hossein Karrubi, told RFE/RL his father was not hurt in the attack.
"The plainclothes agents and [security] forces started beating people and the bodyguards harshly," he said. "They wouldn’t beat [Mehdi] Karrubi himself with their batons, but the bodyguards, companions, and people who were there were badly beaten up. They would shoot paint balls at them, and then they would catch those who were splashed with color and beat them up."
Hossein Karrubi said his father was forced to leave the scene because of the clashes.
"Their reaction was very harsh, and [Mehdi] Karrubi was forced, after several minutes of clashes, to get into the car of one of the people there," he said. "[The security forces] destroyed the car. They broke the windows of the car."
He said he has also received reports that his younger brother, Ali Karrubi, was arrested today.
Protests by opposition members were also reported in the southwestern city of Shiraz, where a student told Radio Farda that at least 20 members of the Green Movement were arrested.
"[Pro-government] forces beat up a young girl, and only when people started to shout, they let the girl go," he said. "They took me, too, and told me, 'Should I strangle you with the [green] scarf you're wearing around your neck.' They asked, 'How much strength did you think you have?' "
Opposition websites reported that opposition supporters took also to the streets of other Iranian cities including Mashad. Jaras website reports that in Mashad more than 100 people were arrested today.WATCH: This video purportedly shows an antigovernment demonstrator being beaten by security forces today.
'For Their Own Safety'
The website Kalameh, which is close to opposition leader Mir Hossein Musavi, reports that the former prime minister was prevented from joining the crowd on Azadi Street. The website also reports that Musavi's wife, Zahra Rahnavard, was attacked and beaten by plainclothes security agents using "their fists and batons." According to the website, she was then surrounded by her supporters and she left the scene shortly after.
Opposition websites are also reporting that former President Mohammad Khatami came under attack today in one of the streets leading to Azadi Square in Tehran and was forced to leave the area in his car.
Reports say Khatami’s brother and his wife, Mohammad Reza Khatami and Zahra Eshraghi, were briefly detained and told to stay home "for their own safety."
Khatami is a former lawmaker; Eshraghi is the granddaughter of the founder of the Islamic Republic, Ayatollah Ruhollah Khomeini.
Iranian authorities had warned the opposition not to disturb today’s celebrations. Eyewitnesses say hundreds of police are deployed in the capital to confront opposition protesters.
Ahead of today’s rallies, Internet and SMS services were disrupted, apparently in an attempt by authorities to prevent opposition activists from communicating and organizing protests.
Despite the Internet restrictions, opposition activists have been managing to send out several videos from today’s protests where people are shouting the name of Musavi and calling for a referendum:
In recent weeks, Iran has stepped up its pressure on the opposition by arresting dozens of journalists, students, and activists and executing two people sentenced in trials that followed the postelection unrest.
The current crisis is the worst in the past three decades, with no sign of compromise from either government or opposition.
Outside of Iran, Radio Farda correspondents in Dubai and Kuala Lumpur report gatherings of several dozen people today in support of Iran's Green Movement.
Radio Farda's Ruzbeh Bolhari and RFE/RL correspondent Farangis Najiballah contributed to this report