A monitoring group says at least 23 Syrian civilians were killed Saturday in suspected Russian airstrikes on a rebel-held town outside Damascus.
The Syrian Observatory for Human Rights said at least six children and seven women were among the dead in the attack on the town of Douma.
A Syrian rescue service operating in rebel areas said at least 24 people were killed, including women and children.
Rebels in Douma often fire rockets into Damascus, and the Douma area is a frequent target of government airstrikes and shelling.
Also Saturday, the observatory said the death toll from Thursday's airstrikes on a city controlled by Islamic State near the Iraq border has risen to 71, up from the original count of about 25. The group said at least six children were among the dead.
Russia, Syria's government and a U.S.-led coalition are all carrying out bombing raids in Syria, sometimes in the same areas.
Meanwhile, an activist group says Islamic State militants have released 37 Syrian Christians, mostly women, who were among more than 200 people from an Assyrian minority group abducted in February.
The Assyrian Human Rights Network said those released arrived Saturday in the mainly ethnic Syrian village of Tal Tamr in northeastern Hasakeh province.
The group said negotiations continue for the release of more than 125 other Syrian Christians who remain in captivity.
Assyrians numbered about 30,000 among Syria's 1.2 million Christians before the country's conflict began in 2011. They lived mostly in villages in Hasakeh. Islamic State militants overran many of the villages early this year, but Kurdish forces later expelled them.