NATO Secretary General Anders Fogh Rasmussen on Friday condemned Syria's "infamous" crackdown on protesters, but said the alliance would not take action in the country.
Unlike in Libya, there was no United Nations mandate nor regional support for such an operation, he said in an interview with the Spanish national television channel TVE.
Rasmussen urged the Syrian authorities to "adapt to the legitimate aspirations of the people."
After a days-long siege, Syrian troops backed by tanks and helicopter gunships seized control early Friday of another northwestern town, activists reported, as fresh accounts emerged of indiscriminate killing and summary executions in the Damascus regime's suppression of a pro-democracy movement.
Elsewhere in Syria, thousands of people took to the streets again after the opposition called for a day of massive demonstrations, pressing on with their 3-month-old campaign to topple authoritarian President Bashar Assad.
Troops in large numbers poured into Maaret al-Numan, 28 miles (45 kilometers) from the Turkish border, said Syria-based rights activist Mustafa Osso. He said other forces were now massing around Khan Sheikhon, to the south, where gunmen attacked army forces earlier this month.
Omar Idilbi of the Local Coordination Committees, which is documenting the protests, said government forces had taken full control of Maaret al-Numan, a town of 100,000 on the highway linking Damascus with Syria's second-largest city, Aleppo. Many of its residents had fled as troops swept through Idlib province in recent days.
There was no immediate word on casualties.
Since the protests erupted in mid-March, Assad has unleashed the military in region after region to crush street demonstrations. Human rights activists say more than 1,400 Syrians have been killed and 10,000 detained. Some 9,600 others from the northwest have sought refuge in camps in neighboring Turkey.
One of those refugees, asking to be identified only as Mohamed, said he fled with his family as the military besieged Jisr al-Shughour, a rebellious town it recaptured last Sunday.
"I saw people who were beheaded with machine-gun fire from helicopters," and man tortured to death when security forces "poured acid on to his body," he told The Associated Press.
He said a sugar factory in the city was turned into a jail where they "hold quick trials and execute anyone who they believe participated in protests."
It's impossible to independently confirm many accounts coming out of Syria. Foreign journalists have been expelled from the country and local reporters face tight controls.
In the northeast, meanwhile, about 2,000 protesters marched in the towns of Amouda and Qamishli shortly after Friday prayers ended, chanting for the regime's downfall, the Local Coordination Committees said.
Friday has become the main day for protests in the Arab world, and Syrians have turned out every week in large numbers nationwide, inspired by democratic revolutions in autocrat-ruled Tunisia and Egypt.
The opposition has attached a name to each Friday's campaign, naming this one "The Day of Saleh al-Ali," an Alawite leader who led an uprising against French colonial rule in the 20th century.
Using an Alawite figure's name was meant to show that Assad's opponents were not rising up over secular concerns. The Assad regime is dominated by the Alawite minority, an offshoot of Shiite Islam, but the country is overwhelmingly Sunni Muslim.
Alawite dominance has bred resentment, which Assad has worked to tamp down by pushing a strictly secular identity in Syria. But the president now appears to be relying heavily on his Alawite power base, beginning with highly placed Assad relatives, to crush the resistance.
The government blames a foreign conspiracy for the unrest, saying religious extremists are behind it - not true reformers. Military chiefs said the northwestern sweep was needed to rid the area of "armed terrorists."
But refugees like Mohamed said they only want freedom. "What is our guilt? We just demanded freedom and democracy nothing else."
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