While the number of protesters, said by some opposition activists to be in the hundreds of thousands, could not be independently confirmed, the size of the protests and their level of coordination suggest that Syria’s fragmented opposition movement is reaching new levels of coherence and organization.
The deadliest clashes were in the southern city of Dara’a, where security forces opened fire on demonstrators, witnesses said. A Syrian human rights activist said 21 deaths had been confirmed, but that figure was likely to rise.
The government, meanwhile, said its security forces had been fired on by armed groups in Dara’a. The Interior Ministry said 19 police officers and members of security forces were killed, in addition to several civilians, the government news agency, Sana, reported. It was the first time the government had made a substantial claim of deaths.
The numbers reported by either side were difficult to verify. Foreign news media have not been permitted to travel outside Damascus, the capital, and state security forces have cordoned off the towns and suburbs where the largest protests took place.
There were also protests on Friday in Damascus, in a suburb where at least 15 protesters were killed by security forces last Friday, and in Kurdish towns in the east.
In Washington, President Obama condemned what he called “the abhorrent violence committed against peaceful protesters by the Syrian government today and over the past few weeks.” He also condemned “any use of violence by protesters.”
Ausama Monajed, a London-based political activist who is in frequent touch with protesters in Dara’a and other cities, said that the protest movement had gained enormous momentum and confidence over the past week. Though Syria lacks a natural mass gathering point like Tahrir Square in Egypt, he said, he estimated that across Syria, total numbers of protesters might add up to hundreds of thousands.
He called the attack on protesters in Dara’a “a massacre.” He feared that the government might be trying to make an example of Dara’a, where the protests began three weeks ago after a group of teenagers was arrested for writing antigovernment graffiti, as it did with Hama in 1982.
“What happened is that after Friday Prayers, the marchers started to chant, ‘Freedom! Freedom!’ and security forces opened fire,” Mr. Monajed said in a phone interview. “When the protesters tried to collect the dead and wounded, the security forces opened fire again.”
There were reports that security forces had closed the hospitals, possibly to forestall further protests at funerals on Saturday, Mr. Monajed said. According to Islamic custom, the dead are buried as soon as possible, and the funerals of protesters in recent weeks have turned into political demonstrations.
Ammar Abdulhamid, a Syrian dissident who lives in Maryland and has helped organize the protests, said that according to his contacts in Dara’a, 100 may have been killed there and as many as 500 wounded.
Though Syria’s protest movement is far more decentralized than it has been in Egypt and Bahrain, Mr. Abdulhamid said, its strength is growing.
“Each community has its own uprising,” he said. “Every week the regime is being forced closer to its endgame.”
The killings in Dara’a on Friday, he said, may have been an attempt by the government “to send a lesson to other cities,” the way Mr. Assad’s father, Hafez al-Assad, massacred at least 10,000 Muslim Brotherhood members in Hama in 1982 to strike fear in Islamists across the country.
Amr al-Azm, a Syrian historian, cautioned that it was not yet clear how broad support for the protest movement was. He said the greatest numbers of protesters were poor, semirural and young, and that the country’s powerful Sunni upper-middle class had not yet decided where it stood.
“The urban upper-middle classes feel uncomfortable with these people,” he said. “The thing about Syria is that in order for these protests to reach the critical mass you need to achieve real change, you have to tap into the merchant classes of Damascus and Aleppo.”
He said that group was unhappy with the government but also concerned about stability.
There were also protests on Friday in the eastern Kurdish areas, two days after Mr. Assad sought to quell unrest there by offering Syrian nationality to the estimated 200,000 Kurds, formerly classified by the government as stateless.
Kurdish leaders and human rights activists rejected the offer.
Hakeem Bashar, a Kurdish leader, said that thousands of people had demonstrated in Qamishli, one of the largest towns in the Kurdish northeast.
“We want all of the demands that other Syrians in other parts of the country are making,” Dr. Bashar said. “These are national demands, but we are demanding them too because this is our country. We are Kurds, but we are also Syrians.”
Security forces have maintained a heavy presence in Damascus. Six buses carrying uniformed and plainclothes officers arrived at the Al Rifai mosque, a center of protests last week, during Friday Prayer, said Wissam Tarif, a human rights activist, pulling open its doors and beating worshipers as they exited.
Security forces scuffled with protesters and hauled others into the waiting buses as they chanted “Freedom! Freedom!”
Villagers outside of Damascus marched toward Douma, a village where security forces fired on demonstrators last week, killing at least 15 people.