Syrian security forces on Friday shot dead seven anti-regime protesters, including two in Daraa, according to an updated toll provided by human rights activists.
Three civilians were killed in the Qabun district of Damascus, and another two were slain in the Bosra al-Harir area of southern Daraa province, an epicentre of pro-democracy protests that have shaken Syria since mid-March.
A sixth person was shot dead in the coastal resort of Latakia, said the head of the London-based Syrian Observatory for Human Rights, Rami Abdel Rahman, reached by telephone from Nicosia.
The seventh fatality occurred near Al-Sirmanya in northwestern Idlib province, another human rights activist told AFP, requesting anonymity.
Idlib has been the focus of a massive security force crackdown in recent days.
The Syrian army also swept in Jisr al-Shughour to seize "armed" opponents, state television said, as tens of thousands of people marched anew around Syria despite Bashar al-Assad's increasing resort to armed repression.
"Long live Syria, down with Bashar al-Assad!" protesters shouted in many of the rallies staged after Friday prayers across the country of 20 million.
Some troops fired from rooftops at marchers, activists said.
"There was a demonstration of 1,000 people when security police fired from their cars," a Bosra al-Harir resident said, giving the names of the dead as Abdelmuttaleb al-Hariri and Adnan al-Hariri. The latter was an amputee, residents said.
However, state television said unidentified gunmen killed a member of the security forces and a civilian in Bosra al-Harir.
Syria has barred most independent media from the country, making it difficult to verify accounts of the bloodshed.
Witnesses told Reuters by telephone that some of the protesters shot by security forces in Daraa -- including two who were hit in the head and chest -- were hurriedly carried by youths to a nearby makeshift clinic.
Almost 3,000 Syrian civilians have fled cross the northwest border into Turkey, Turkish officials said Jisr al-Shughour largely emptied of people in the face of a looming military operation following clashes earlier this week.
A Turkish newspaper said Ankara was looking into creating a buffer zone along the border as a contingency if hundreds of thousands of Syrians wound up fleeing the military campaign to stamp out protests against 41 years of Assad family domination.
Syrian authorities said that "armed gangs" killed more than 120 security personnel in Jisr al-Shughour, a town of 50,000.
But rights campaigners said scores of civilians were killed after some soldiers refused to shoot at protesters and fighting broke out between loyalist and mutinous forces.
Human rights activists aired a YouTube video purporting to be from Lieutenant Colonel Hussein Armoush saying he had defected with several soldiers to "join the ranks of the masses demanding freedom and democracy.
"We had sworn in the armed forces to direct our fire at the enemy and not on our own defenceless people. Our duty is to protect citizens and not to kill them," he said in the video, whose authenticity could not be immediately verified.
Fifty-seven Syrians from Jisr al-Shughour were in hospital in Turkey, its state-run Anatolian news agency said on Friday.
The border area, like other protest hotspots, is prone to tension between majority Sunni Muslims and Assad's Alawite sect, which dominates the Syrian power elite. The Jisr al-Shughour violence may hint at divisions within security forces, where commanders are mainly Alawite and conscripts Sunni, that would increase the risk of Syria descending into civil war.
Demonstrators demanding the "downfall of the regime" and chanting slogans in support of compatriots in Jisr al-Shughour took to the streets in the oil-producing eastern province of Deir al-Zor, the central cities of Hama and Homs, the main Mediterranean port of Latakia and the Tabaqa region on the Euphrates River in Raqqa province, activists and residents said.
Tens of thousands of people marched unchallenged in Hama, they said, well above the turnout of the previous Friday when security forces killed at least 70 protesters.
Protests were also reported in five Damascus suburbs, Syria's second largest city Aleppo and Maarat al-Numan near Jisr al-Shughour, but their size was not immediately clear.
In a report on developments in Jisr al-Shughour, a state television announcer said that "in response to people's calls, units from the Syrian Arabic Army started its duties ... to arrest armed members".
Inhabitants said at least 15,000 troops along with some 40 tanks and troop carriers had deployed near Jisr al-Shughour, and that the area had largely emptied of civilians.
"Jisr al-Shughour is practically empty. People were not going to sit and be slaughtered like lambs," said one refugee who crossed on Wednesday and who gave his name as Mohammad.
Residents said troops and armoured vehicles heading for the town had stormed Sarmaniya village, 10 km (six miles) south of Jisr al-Shughour, and cut off the region's communications.
"They began as usual by firing heavy machineguns into the village. But the people of Sarmaniya had mostly left. Hundreds of troops and security forces have defected in the last several days. They (pro-Assad forces) might be thinking that they will find some in Sarmaniya," said the witness, who was speaking by phone from the outskirts of Jisr al-Shughour.
The International Committee of the Red Cross (ICRC) urged Syria to allow its aid workers wider access to the civilian population without further delay, including people who have been wounded or detained in the military clampdown on public dissent.
Rights groups say over 1,100 civilians have been killed since March in the revolt to press demands for more political freedoms and an end to corruption and poverty.
The latest reports of Assad's military campaign against protesters intensified international concerns over his handling of popular pressure for democratisation inspired by uprisings against entrenched autocrats elsewhere in the Arab world.
US Defence Secretary Robert Gates said on Friday the legitimacy of Assad's rule was open to question. "I would say the slaughter of innocent lives in Syria should be a problem and a concern for everybody," Gates told a seminar in Brussels.
"Whether Assad still has the legitimacy to govern his own country, I think is a question everyone needs to consider."
Britain, France, Germany and Portugal have asked the U.N. Security Council to condemn Assad, although veto-wielding Russia has said it would oppose such a move.
World powers have shown no appetite for any Libya-style military intervention in Syria because it sits on a major fault line of Middle East conflict, allied with Iran against nearby Israel. The Syrian leadership has shrugged off mild punitive sanctions imposed so far, and verbal reprimands from abroad.
On the Turkish side of the frontier on Friday, a Reuters news team saw three Syrians lying wounded on the ground as ambulances arrived to collect them. Turkish minibuses were collecting other Syrians and taking them to a nearby camp.
Anatolian news agency said the number of Syrians seeking refuge across the border had reached 2,792, with more crossing the hilly, wooded frontier on Friday.
At the Yayladagi refugee camp, nestled in a scenic valley close to the Syrian frontier, children played football while families sat talking under trees sheltering them from the baking Middle East summer sun. Police kept journalists away.
Turkish Prime Minister Tayyip Erdogan reiterated on Thursday that Turkey would keep its gates open to people from Syria. But he complained that Damascus was taking the issue "very lightly" and Ankara could not defend its "inhumane" reply to the unrest.
Assad, 45, has promised reforms, even while cracking down on unrest posing the gravest threat to his 11 years of iron rule.