BEIRUT -- Hundreds of thousands of protesters flooded cities around Syria on Friday in what activists described as the largest outpouring against the regime of President Bashar Assad and a powerful message of the opposition's resolve. At least 14 people were killed in various clashes, activists said.
The wildfire rage -- flaring in dozens of places at the same time -- further strained the resources of Assad's security forces and military as they also try to choke off a refugee wave into Turkey.
The centerpiece of the latest protests -- the central city of Hama -- brings further complications for the government. Security forces moved outside Hama in early June after shootings that left 65 people dead, and now the streets appear fully under the sway of the opposition with an estimated 300,000 people gathering Friday in the central square, activists said.
Crowd estimates and other details cannot be independently verified. The Syrian government has banned most foreign media from the country and restricted coverage.
But the protest surge Friday appeared to dwarf recent weeks as Assad's forces tried to wear down the opposition with relentless force. Syrian rights groups say more than 1,400 people have been killed, most of them unarmed protesters, since mid-March.
The regime disputes the toll, blaming "armed thugs" and foreign conspirators for the unrest that has posed the most serious challenge to the Assad family's 40-year ruling dynasty in Syria.
In Hama, anti-government crowds defiantly staked their claim to the city -- which carries important symbolism to the opposition. In 1982, Assad's late father, Hafez Assad, stormed the city to crush an uprising, leaving between 10,000 and 25,000 people dead, rights groups say.
Syria-based activist Mustafa Osso estimated 300,000 people joined the rally in Hama without any sign of security forces, which remained outside the city and appeared unwilling to risk major bloodshed again.
It also could reflect fatigue in Assad's core troops and the need to concentrate on what officials consider strategic fronts. Assad's elite forces have waged nearly nonstop crackdowns around the country as new protest hotbeds emerged.
Now, they are mobilized in difficult terrain along the Turkish border in efforts to clamp down on refugees fleeing across the border. The regime is deeply embarrassed by the exodus and also fears the camps could become opposition enclaves out of the government's reach.
"Syrian security forces are exhausted," said Osso. "There are demonstrations all over Syria and they cannot cover these areas."
In Lithuania, U.S. Secretary of State Hillary Rodham Clinton called on Assad's regime to either begin a credible political reform process or "continue to see increasingly organized resistance."
"It doesn't appear that there's a coherent and consistent message coming from Syria," Clinton told a news conference. "We know what they have to do. They must begin a genuine transition to democracy and allowing one meeting of the opposition in Damascus is not sufficient action toward achieving that goal."
Osso said huge protest crowds moved into the streets after the Muslim noon prayers in places across the country, including the capital Damascus. Some carried red cards to copy the "send off" signal by soccer referees.
A video posted on the Local Coordination Committees' Facebook page showed dozens of people marching outside a mosque in Damascus' central neighborhood of Midan as they chanted "Bashar out, Syria is free."
Omar Idilbi, a spokesman for the Local Coordination Committees, which track the protests in Syria, said Friday's demonstrations were the largest since the uprising began in mid-March. He did not give a figure, but said there were gatherings in 172 different locations with numbers ranging from few hundreds to hundreds of thousands as in Hama.
Activists -- including Idilbi and the Local Coordination Committees -- said at least 11 people were killed by security forces around the country, including five in the central city of Homs and two in Damascus.
In separate clashes, three people were killed during a military operation seeking to halt the flow of refugees heading across the border to Turkey, said Rami Abdul-Rahman, the London-based director of the Syrian Observatory for Human Rights.
More than 10,000 Syrians have already taken shelter in refugee camps in Turkey to escape the violence.
State-run Syrian TV aired footage of pro-government demonstrators in different parts of the country carrying Syrian flags and posters of Assad. State TV said gunmen opened fire at police officers, killing a police officers and a civilian.
Although Syria's northern border with Turkey, Syrian forces have been combing through villages and hinterlands hunting down soldiers who abandoned their weapons and trying to quell demonstrations.
An activist said some villagers have fled as Syrian soldiers neared.
"They are ghost towns," said the activist, who spoke on condition of anonymity because of fear of reprisals.
In the same area Friday, the activist said other villagers were marching toward the Roman-era city of Barah, where he said Syrian forces had encircled the town of some 20,000 people and positioned snipers on rooftops. Power and water supplies to the city were cut, the activist said.
Turkish officials said Friday 113 refugees have returned to Syria since Thursday and there were no new arrivals. They said the number of refugees still in Turkey is 10,497.