Syrian forces executed 44 men near a mosque in the northern province of Idlib, the Doha-based Al Jazeera television reported Tuesday.
"The men were executed late Monday near al-Bilal mosque and their bodies were found early Tuesday," the broadcaster quoted activists in the area as saying.
The Syrian Observatory for Human Rights said that clashes had erupted between government forces and defectors in several areas across Idlib.
Meanwhile, government security forces continued their assault on rebels in central and northern Syria on Tuesday, prompting scores to flee to neighboring countries, activists said.
"Tanks have been shelling Idlib's provincial capital with heavy artillery since the early morning," activist Mohamed Abdullah said.
"Women and children have been taken hostage in cities inside the province of Idlib to pressure their sons or husbands who have joined the revolution to hand themselves in," he added.
The shellings have prompted many who live in areas near Syria's northern borders to flee into Turkish territories.
"People are scared that, if they stay, they will face the same fate of people who have been slaughtered in Homs over the weekend," Abdullah said.
According to the Syrian opposition and activists, the bodies of 57 women and children were found, some of them with their throats slit, in the neighborhood of Karam al Zeitoun in Homs province over the weekend, after being killed by regime forces.
Activists at the Lebanese-Syrian border said around 35 families had arrived late Monday in Lebanon's port city of Tripoli after escaping the region of Homs.
According to a report released Tuesday by the New York-based Human Rights Watch, Syrian troops have planted landmines along routes used by people fleeing the country's violence and trying to reach neighboring Turkey.
Activists said some 700 people were killed and thousands wounded during the 30-day assault last month by government forces on restive areas in Homs. The UN Human Rights council said during a meeting in Geneva on Monday that the "desperate situation" of civilians in Syria needed to be addressed as a matter of utmost urgency.
The UN has put the death toll at more than 7,500, including 500 children, in the year since a crackdown began on protesters seeking the ouster of President Bashar Assad.