The Russian defense ministry said its soldiers bombed nine ISIS positions Saturday near the terror group's de facto capital in Raqqa.
In the past 24 hours, the air force conducted 20 airstrikes near Raqqa, the ministry said.
Tactical bombers destroyed various militant facilities, including ammunition and oil depots, and all-terrain vehicles, the defense ministry said in a statement.
At least 11 people were killed in an alleged double strike by Russia in Syria's Idlib province, according to opposition groups.
Members of Syria's Civil Defense, a volunteer group operating in rebel-controlled areas, rushed to save people after the aerial attack on the village of Ehsim when a second strike hit the area. A rescue worker and nine members of one family were among the dead, according to the rebel-run Revolutionary Forces of Syria.
"There were families living there," said Ahmed alHmady, head of Syria Civil Defense in Balyoun, Idlib, who survived the attack. "There are no armed fighters there."
CNN could not independently verify it was a Russian strike. Syria and the U.S.-backed coalition against ISIS have also launched strikes.
Russia's defense ministry reported aerial strikes in Idlib but did not say what villages were hit.
Col. Gen. Andrey Kartapolov said Russia notified the United States of the airstrikes in advance.
"The U.S. military attache to Iraq was the first to be informed by our representative in Baghdad, Gen. Kuralenko, on Wednesday morning," Kartapolov said, according to Tass. The official said that Russia also notified the U.S. side through diplomatic channels.
New day, more bombs
Saturday marks the fourth day Russia has carried out airstrikes in Syria.
And with every passing day, the international community raises alarms over Moscow's intentions.
In a joint statement, a coalition made up of the United States,
Britain, Turkey, France, Germany, Qatar and Saudi Arabia accused Russia of attacking the Syrian opposition and civilians, instead of fighting ISIS.
"These military actions constitute a further escalation and will only fuel more extremism and radicalization," the statement said.
It questioned whether Russia's primary concern is attacking ISIS or propping up Syrian President Bashar al-Assad
Russia defends airstrikes
Russia has denied it conducted any strikes against civilians, and maintained it is targeting the brutal militant group.
"There were no strikes against civilian infrastructure, especially against buildings where there could have been or were peaceful residents," the defense ministry said.
As the diplomatic squabble grows, the White House downplayed Russia's decision
to launch the strikes without coordinating with the United States.
Russia gave the U.S. a one-hour warning before it launched airstrikes in the western Syrian city of Homs on Wednesday. Moscow told the U.S. aircraft battling ISIS in Homs to leave Syrian airspace.
The U.S. force did not leave, raising the possibility of military mishaps between the two powers as their forces operate in the same area.
The Pentagon has suggested Russia is backing close ally al-Assad -- who appears to be losing his grip on power as the nation's years-long civil war continues unabated.
U.S. defense officials have warned that Russia's move will inflame the civil war and set back efforts to drive out ISIS.