Syrian opposition groups have reported fierce battles between regime troops and armed rebels in the capital Damascus. A day earlier US President Barack Obama called for a "political transition" to end violence in Syria.
The Local Coordination Committees and the Syrian Observatory for Human Rights said fierce fighting broke out early Sunday in the restive district of Kfar Souseh. Gunfire was also reportedly heard in several other neighborhoods.
"Violent clashes broke out between rebel fighters and regime troops at a checkpoint in Kafr Sousa district," the Syrian Observatory for Human Rights said in a statement. There have been no immediate reports of any casualties.
Clashes also broke out in other parts of southern Damascus, the London-based Observatory said, adding that gunfire was reportedly heard in several neighborhoods in the capital.
"Gunfire was heard in Abbasiyyin Square, and Baghdad and Thawra streets," said the watchdog, referring to high-security areas of the city.
The fighting comes a day after the Observatory said at least 23 people had died in violence across the country, including nine people killed in a car bomb attack in the eastern city of Deir Al-Zour.
There was no immediate claim of responsibility for the bombing, which coincided with the G8 leaders' talks at Camp David, outside Washington, where Syria's perilous situation was high on the agenda.
G8 urges political transition
According to US President Barack Obama, the G8 leaders agreed that the political process in Syria should move forward "in a more timely fashion" in order to end relentless violence in the country.
"We had a discussion about Syria, we all believe that a peaceful resolution and a political transition in Syria is preferable," he said.
Obama reportedly also told G8 leaders that Syrian President Bashar al-Assad must step down, pointing to Yemen as a model for reforms.
In a statement summarizing talks, meanwhile, the G8 said they wished to urge all parties in Syria to adhere to their commitments under a joint UN-Arab League peace plan "including immediately ceasing all violence so as to enable a Syrian-led, inclusive political transition leading to a democratic, plural political system."
The United Nations estimates that some 9,000 people have been killed in Syria since the anti-regime uprising began in March 2011.
ccp/tm (AFP, AP, Reuters)