Syrian security forces have opened fire on anti-government protesters, killing at least eight people, reports say.
The incidents occurred after Friday prayers in a Damascus suburb, a town in the south and near the Lebanese border.
Last Friday after prayers, at least 44 people died after demonstrations calling for President Bashar al-Assad to step down.
The Group of Eight said it was "appalled" at the bloodshed, and urged an end to the use of force.
"We call on the Syrian leadership to immediately stop using force and intimidation against the Syrian people and to respond to their legitimate demands for freedom of expression and universal rights and aspirations," leaders said after a meeting in Deauville, France.
Human rights groups say more than 1,000 people have been killed in Syria since the uprising began ten weeks ago.
On Friday, at least three people died in Qatana, a suburb of Damascus, where some 1,500 people had gathered to protest.
One person was killed in the town of Zabadani, near the Lebanese border, and a further four died in the southern village of Dael.
One eyewitness, who did not want to be named, said security forces had entered Dael in the early hours of the morning.
"They spread through the streets and surrounded it. They started shooting gunfire and combed the city using tanks," he told BBC Arabic.
There were also reports of protests in the cities of Baniyas, Homs and Rastan with some 5,000 people gathering in Deir Ezzor.
In Homs, the site of some of the largest demonstrations in recent weeks, security forces did not open fire on protesters but closed all the roads leading to the city centre.
Protesters in the central city could be heard chanting "Allahu Akbar" (God is Great), "Down with the regime" and "Get out, get out," to the president.
Many activists are reported to be choosing to demonstrate under the cover of nightfall when there are fewer security officials on the streets.
According to AP, live rounds were fired on a late-night protest in the town of Deraa overnight on Thursday.
"We refuse to let them sleep," a 28-year-old Dael resident said of the security forces, according to AP.
"We drive them crazy: as soon as they come to the neighbourhood we go quiet and they get lost. And then we start again when they leave," he said.
He said that three of those who died in Dael were cousins from the same family.
Syria has banned foreign journalists, making it difficult to verify eyewitness accounts. Syrian authorities insist they are pursuing "armed terrorist gangs".