(CNN) -- Arab League foreign ministers are set to convene Saturday to discuss the Syrian crisis as other world leaders quarrel over who is fueling the spiraling conflict.
While global talks and international jabs continued, opposition activists reported fresh scenes of violence and bloodshed across Syria on Saturday.
Warplanes flew over the anti-government bastion of Homs as the regime's armored vehicles raided the city amid heavy gunfire, the Local Coordination Committees of Syria said. The opposition network also said government forces stormed the city of Daraa, deploying snipers and burning homes.
At least two people, including a defected soldier, were killed Saturday, the opposition Syrian Observatory for Human Rights said.
After the top U.S. diplomat accused Russia of "propping up the regime" of Syria's embattled president, Russia struck back Friday by denying arms sales to Damascus and saying international efforts may have fueled instability and violence.
U.S. Secretary of State Hillary Clinton hammered home her claim Friday that Moscow is helping its longtime ally in Damascus through a "very consistent arms trade" that "has strengthened (President Bashar al-Assad's) regime."
"The fact that Russia has continued to sustain this trade in the face of efforts by the international community to impose sanctions and to prevent further arms flowing to the Assad regime, and in particular the Syrian military, has raised serious concerns on our part," Clinton said.
Russian President Vladimir Putin responded hours later by flatly denying "any trading connections (or) military" with its longtime ally Syria.
"The only thing that concerns us in (Syria) is the possibility of radicalization of the situation, the situation getting out of control and the deaths of civilians," Putin said from France after meeting new French President Francois Hollande. "Our aim is to bring the conflict to peace."
But Russian Foreign Ministry spokesman A.K. Lukashevich spoke more forcefully Friday, asserting that some international efforts -- including threats of military intervention -- have exacerbated the crisis, bringing Syria closer to civil war and making it easier for "strong religious elements (to) come to the forefront."
Lukashevich accused "international and regional players" of pushing an agenda to get al-Assad ousted.
But Hollande is among the corps of world leaders who say al-Assad must go.
"There will only be an exit possible with the departure of Bashar al-Assad," Hollande said.
Meanwhile, the U.N. Human Rights Council on Friday authorized the U.N.'s Independent International Commission of Inquiry on Syria -- which has issued ongoing reports about violence in the country -- to conduct a robust probe into the Houla massacre last week that left 108 people dead, including 49 children.
Meeting in Geneva, Switzerland, 41 countries voted for the resolution while Russia, China and Cuba voted against it. Russia and China have vetoed U.N. Security Council attempts to formally condemn the al-Assad regime.
U.N. human rights chief Navi Pillay said the killings in Houla "may amount to crimes against humanity and other international crimes, and may be indicative of a pattern of widespread or systematic attacks against civilian populations that have been perpetrated with impunity."
Syria told Pillay's office that "terrorist armed groups" were responsible for Houla massacre. It said the military "was acting only in self-defense" and sought to protect civilians.
Syria's representative to the Human Rights Council, Faisal al-Hamwi, said he thinks the "terrorists" are linked to groups "whose main motive was to ignite sectarian sedition in a region with a multi-community social fabric," the state-run Syrian Arab News Agency reported.
But opposition activists and residents have said pro-regime forces went house to house, lining up residents and shooting them.
Sectarian tensions have been high in Houla, which is overwhelmingly Sunni and is surrounded by Alawite and Shiite villages. Al-Assad's regime is dominated by Alawites.
The crisis in Syria began nearly 15 months ago, when a tough government crackdown on protesters last year spiraled out of control and spawned a national anti-government uprising.
Fresh reports of summary executions have emerged this week. In the Homs province village of Bouyda, 12 factory workers were killed Thursday by pro-government gangs known as Shabiha, the opposition Syrian Observatory for Human Rights said. They were lined up against a wall and shot, the group said.
On the other side of the country, U.N. observers said the bodies of 13 people were discovered about 30 miles east of Deir Ezzor on Tuesday night.
CNN cannot independently confirm death tolls or reports of violence from Syria because the government limits access to the country by foreign journalists.