A Russian reconnaissance aircraft carrying 15 people on board is brought down by a Syrian surface-to-air missile over the Mediterranean Sea.

On 17 September 2018, the Israeli Air Force (IAF) conducted missile strikes against multiple targets in government-controlled western Syria. Syrian air defences responded to the Israeli fighter jets, accidentally shooting a Russian military Il-20, killing 15 crew aboard. Russia blamed Israel for the loss of its plane, accusing the IAF of "hiding behind the Russian aircraft", thereby putting it in the line of fire. The Israel Defense Forces acknowledged striking a Syrian weapons facility, and expressed sorrow for the loss of lives due to Syrian fire. The strikes occurred a few hours after a Russo-Turkish agreement to create a demilitarized zone around Idlib Governorate was achieved, which postponed an imminent offensive operation by Syria's forces and its allies.

September 17 is the 260th day of the year in the Gregorian calendar; 105 days remain until the end of the year.