BEIRUT – Thousands of Syrians flooded streets across the country Friday, defying an unrelenting government crackdown that has failed to crush a two-month uprising against the country’s authoritarian regime.

Human rights activists said security forces opened fire, killing at least 27 people, including a 10-year-old boy.

Friday’s turnout — and the now-familiar deadly response by the regime — was the latest sign the conflict could be moving toward a dangerous stalemate. President Bashar Assad’s forces have unleashed tanks and snipers and made thousands of arrests to break the revolt, but protesters continue to face down security forces.

Protesters insisted their movement was growing and they would not be bowed.

“We, as young activists, are very optimistic,” said a protest organizer in the capital, which saw at least four separate demonstrations Friday — a significant increase from recent rallies in Damascus, at the heart of the Assad regime’s power. Like most protesters contacted by The Associated Press he asked that his name not be used for fear of government reprisals.

Assad has shrugged off U.S. calls to step aside as well as a new round of sanctions targeting him and top aides, suggesting mounting international pressure will not force an end to a crackdown that human rights groups say has killed at least 900 people since mid-March.

Friday’s crushing security response came despite calls a day earlier from President Obama that Assad should lead his country to democracy or “get out of the way.” Syria’s official news agency said Obama’s admonition amounted to “incitement.”

The revolt has posed the most serious challenge to the Assad family’s 40-year ruling dynasty.

Protesters have yet to bring out the sustained massive daily protests that brought down the leaders in Egypt and Tunisia, and analysts say it’s too soon to say whether Assad can survive the upheaval.

Assad’s sweeping campaign of intimidation, mass arrests and heavy security kept crowds last week below earlier levels seen during the uprising. But larger and more widespread marches Friday suggest that opposition forces could be trying to regroup.

“There were large numbers from the south to the north to the suburbs, and there were protests in besieged cities and towns,” said Rami Abdul-Rahman, director of the Syrian Observatory for Human Rights.

Witnesses reported protests in the central cities of Homs and Hama, the capital of Damascus and its suburbs, and the Mediterranean ports of Banias and Latakia. In the northern city of Aleppo, Syria’s second-largest city, security forces using batons quickly dispersed dozens of demonstrators, an activist said.

Human rights activist Mustafa Osso said the army deployed tanks around the northern town of Maaret al-Numan, which has seen intense protests. The Local Coordination Committees in Syria, which help organize the protests, said dozens of people were wounded in the town.