A pair of U.S. Air Force F-22 Raptor stealth fighters fired flares to chase two Russian Su-25 fighter jets out of restricted airspace over Syria on Wednesday, a Pentagon official confirmed Thursday.

The aerial encounter occurred when the Russian jets strayed into airspace east of the Euphrates River, putting them on the wrong side of a "deconfliction zone" established between Moscow and Washington to avoid confrontation in the skies over Syria.

The Russian jets immediately left the area after the intercept and warning flares from the F-22s, an official confirmed to the Washington Examiner.

The Pentagon could not provide an account of how many or how often Russian violations of the deconfliction zone occur.