Syria's loosely organized pro-democracy movement drew tens of thousands of people into the heart of Damascus and cities across the country Friday, a major victory against a government campaign of violence that has killed hundreds of peaceful protesters.
Activists said security forces, who have deployed tanks in some cities, killed 64 people Friday as they tried to crush the 6-week-old protest movement.
In Washington, the White House said President Obama had signed an executive order imposing sanctions on three Syrian officials the United States believes engaged in human rights abuses.
The protesters appeared to have overcome a psychological barrier, pouring into the streets despite the violence unleashed by security forces last weekend, when at least 120 people were killed. And for the first time, large protests broke out in the heart of Damascus, in the Maidan district, according to witnesses reached by telephone and amateur video posted to the Internet.
"The people want the downfall of the regime," protesters shouted as they marched with banners in the district just southwest of the capital's Old City.
"Everyone wants freedom and dignity, and we will cooperate with our brothers to attain these things," said an engineer marching in Maidan, who was reached by telephone. "We can't watch this oppression. We don't care if we are detained. If they want to detain us then so be it. The barrier of fear has been broken."
The scale of Friday's demonstrations suggested that the regime's use of extreme force had failed to quell the protesters' determination, and may have even outraged some who earlier were on the sidelines.
"To heaven we go, martyrs by the millions," protesters chanted in Deir Alzour, a city in the country's east, according to video posted online.
Syrian security forces responded to the protests with gunfire, and the toll rose through the evening. Among those killed was an 11-year-old child in the western city of Homs, said a medical source who spoke on condition of anonymity.
"There are still many wounded in the streets and we can't get to them," said the medical source. "The army was firing at protesters."
At least five people were killed on the outskirts of the southern city of Dara, where the uprising began. The city has been all but occupied by the army's fourth armored division, which is under the command of President Bashar Assad's brother Maher.
One video posted on the Internet from the village of Sheik Meskeen, 20 miles from Dara, shows a small group of protesters coming under an intense barrage of automatic weapons fire. As the shooting subsides, protesters attend to the lifeless body of one demonstrator. More video purportedly taken later in the village appears to show army tanks and trucks moving through the streets as soldiers open fire at unseen targets.
But in many other areas, security forces appeared absent as protesters took over entire squares, draping banners from balconies and clapping in celebration.
The disparate responses could be evidence of rifts in the security forces rumored by witnesses and activists. Or they could suggest a lack of personnel to put down a rebellion that appears to be breaking out in even the most obscure corners of the nation, a linchpin in the security architecture of the Middle East.
Either way, the day spelled trouble for Assad's regime. Its use of violence, propaganda and a campaign of ongoing arrests failed to halt or stop the protests' momentum. The country is also coming under increased international scrutiny. Turkey, which had been improving ties with Syria, has allowed antigovernment activists to mobilize in Istanbul.
U.S. officials targeted Maher Assad, as well as Atif Najib, the former head of security for Dara, and Ali Mamluk, director of the General Intelligence Directorate. The sanctions will freeze any assets the three men have in the United States, bar U.S. companies from doing business with them and ban them from traveling to the U.S.
They are believed to have few, if any, assets in the U.S., but officials said they hoped the move would encourage sanctions by the European Union, and help persuade the regime to change its ways. The White House stopped short of imposing sanctions on the Syrian president, whom it has courted for two years as a potential ally on regional security issues.
It was not clear whether there were more protesters in Friday's antigovernment demonstration than on previous days. But videos were uploaded to the Internet from every corner of the country, and more quickly than ever. Protesters held up painted banners voicing solidarity with the people of Dara and calling for democratic change.
New protests broke out in long-restive regions, such as the coastal city of Baniyas, and throughout the volatile suburbs of the capital.
"We're the youth revolution, not thugs or terrorists," they chanted in the Damascus suburb of Siqba.
But there were also protests in small towns such as Kafr Zayta in the northwest, Jassem in the south, Derbassiye in the ethnic Kurdish northeast and previously quiet cities such as Raqqah, according to videos posted to the Internet, witness accounts and activists.
In Homs, the country's third-largest city and located on the Lebanese border, activists set up live-streaming video coverage of the marches, suggesting a new level of technological know-how to overcome the regime's restrictions on media.
Syrian opposition activists had called for protests following early afternoon prayers Friday against the violent crackdown on democracy advocates.
Assad's deputies claim the uprising is being fueled by Salafists, puritanical Muslims, and backed by Western powers who oppose Syria's foreign policy.
A military source quoted by the official Syrian Arab News Agency said that a "terrorist" group stormed an army post in Dara on Friday and killed four soldiers. An Interior Ministry source was quoted as saying that three police officers were killed in Homs. Neither claim could be verified because Western journalists have been barred from entering Syria.
Syrian activists scoffed at claims they were being led by armed Islamic extremists.
"We don't have rocks, we don't have sticks, and we don't have knives," said the engineer in Damascus. "We are not Salafists. Many of us are against the Muslim Brotherhood.
"We don't want international military interference but we want support from the international community. We want the help and encouragement of international organizations. We want to live in freedom and dignity."
Special correspondents Meris Lutz and Roula Hajjar in Beirut and Times staff writer Paul Richter in Washington contributed to this report.