The Foreign Ministry said Monday that it was concerned by reports of bloodshed in the Syrian city of Hama and called for an end to the violence.
The UN Security Council scheduled closed-door consultations for later Monday as Syrian tanks shelled Hama for a second day, killing at least four civilians, residents said, in an assault to try to crush protests against Syrian President Bashar al-Assad.
The killings in the city's residential Hamidiyah district brought to 84 the number of civilians reported killed in a tank-backed crackdown on the central Syrian city.
"Moscow is seriously concerned by information about numerous casualties," the Foreign Ministry said. "The use of force against civilians and representatives of state structures is unacceptable and must cease."
It was unclear how Russia would respond to any new push for sanctions in the UN Security Council, where practical action on Syria has been paralyzed for weeks by disagreements within the 15-nation body.
Western European countries circulated a draft resolution two months ago that would condemn the Syrian crackdown on protesters, but Russia and China, both allies of Damascus, have threatened to veto it.
Temporary council members Brazil, India, Lebanon and South Africa have also said they do not support the resolution. Critics say they fear that even a simple condemnation could be the first step toward Western military intervention in Syria, as happened in Libya in March.
Reed Brody, a spokesman for Human Rights Watch, criticized countries for blocking UN sanctions.
"These countries have blood on their hands," he said, adding that the Syrian people were paying the price for what was perceived as an "endless" foreign intervention in Libya.
"So China and Russia and these countries are saying, 'Oh no, we are not signing up again,' but the problem is that by refusing to act they are allowing the massacres to continue. So the Syrian people are paying for the mistakes being made in Libya."
Also Monday, the European Union extended sanctions against al-Assad's government, imposing asset freezes and travel bans on five more people associated with a bloody crackdown on dissent.