At least 36 people have been killed in air strikes by Russian and Syrian jets on Islamic State-controlled Deir Ezzor province, a monitor said.
Russia pounded the jihadist group in Syria, firing cruise missiles from warships in the Caspian Sea after President Vladimir Putin vowed retaliation for the bombing of a Russian aircraft in Egypt last month.
At the United Nations, member states called for action against Isis a week after 130 people were killed in Paris terror attacks.
"At least 36 people were killed and dozens more injured in more than 70 raids carried out by Russian and Syrian planes," said Rami Abdel Rahman of the Syrian Observatory for Human Rights monitoring group.
Russia began bombing in Syria in September at the request of President Bashar al-Assad, while a US-led coalition is conducting its own air campaign against Isis.