Russia has accused the U.S. of endangering a cease-fire in the Syrian province of Idlib by conducting an airstrke there.
Russia said the "indiscriminate" attack was launched Saturday "without advance notice" to Russia or Turkey, which have troops in Idlib.
The U.S. Central Command said Saturday that "U.S. Forces conducted a strike against al-Qaida in Syria [AQ-S] leadership at a facility north of Idlib."
The statement said the operation "targeted AQ-S leaders responsible for attacks threatening U.S. citizens, ... partners and innocent civilians."
Russia's defense ministry said in a statement the attack "compromised the cease-fire in the de-escalation zone of Idlib."
The ministry said "great losses and destruction" were caused by the strike.
The Britain-based Syrian Observatory for Human Rights said the air strikes killed at least 40 militants.
