The Islamic State group Saturday freed 37 Assyrian Christians who were among the 220 hostages it captured in February. Above, relatives of Lebanese soldiers being held captive in Syria by Islamic extremists stage a sit-in outside Lebanon's governmental palace in Beirut to pressure the government to work on securing their release Oct. 28, 2014. Joseph Eida/AFP/Getty Images

UPDATE 10:45 a.m. EST: The Syrian Observatory for Human Rights reported 23 civilians were killed in Russian airstrikes Saturday in Douma, just outside Damascus, AFP reported. At least six children reportedly were among the dead.

Original post:

The Assyrian Monitor for Human Rights Saturday reported the Islamic State group freed 37 Assyrian Christians who were among 220 people kidnapped in Syria more than eight months ago, according to Agence France-Presse. The Syrian Observatory for Human Rights confirmed the release of the mostly elderly 27 women and 10 men. They arrived in the town of Tal Tamr in the Khabur region of Hasakeh province, AFP reported.

The extremist group formerly known as either ISIL or ISIS captured the Assyrians when it overwhelmed parts of the Khabur region in February. Since then, a few of the captives have been released, but the militants still are suspected of holding as many as 150. It was unclear whether the release Saturday was the result of negotiations between the Islamic State group and one of the Assyrian Christian churches or the payment of a ransom. Before the conflict began more than four years ago, there were some 30,000 Assyrians among Syria's 1.2 million Christians, scattered over 35 villages.

The hostage release came amid escalating violence in Syria as Russia steps up its bombing campaign against all rebel groups in the wake of last weekend's crash of a Russian passenger plane in Egypt, for which an Islamic State-affiliated group claimed responsibility.

Time reported six F-15C fighters arrived in Turkey Friday amid that country's complaints Russian planes had violated Turkish airspace. The U.S. Air Force said the planes will "conduct combat air patrols" of Turkish airspace and also may be used to escort bombers attacking Islamic State group targets in Syria. Meanwhile, Russia has deployed Buk anti-aircraft missile systems to Syria, even though the rebels don't pose that kind of threat. The Buk is what brought down Malaysia Airlines Flight 17 over eastern Ukraine last year, killing all 298 aboard.

The Islamic State-related offshoot that claimed it brought down Metrojet Flight 9268 over the Sinai Peninsula last Saturday, killing all 224 aboard, said the action was taken in retaliation over Russian airstrikes in Syria. The New York Times reported the incident, even should it be proven to be the result of a terrorist act, likely would do little to change Russia's course in Syria. Russian President Vladimir Putin said at the beginning of his country's involvement in Syria that it was a fight against terrorism and that the only way to succeed is to "act pre-emptively, to fight and destroy fighters and terrorists on territory they have already seized, and not to wait until they come to our house."