The United States acknowledged on Saturday that its warplanes had carried out an airstrike in Syria that resulted in the deaths of Syrian government troops. American military officials said the pilots in the attack, in the eastern province of Deir al-Zour, believed they were targeting the Islamic State.

Russia’s defense ministry said the United States attack had killed 62 Syrian troops, wounded 100 more and opened the way for an Islamic State offensive.

The episode comes at a time of escalating tensions in Syria. A partial cease-fire that started on Monday continues to steadily unravel after it was declared with much fanfare by the United States and Russia.

A statement by United States Central Command said that the planes stopped the attack after a warning from Russia that the strikes could be hitting Syrian troops.