A U.S. fighter jet shot down a Syrian bomber Sunday, leading to a warning from Russia that "any flying object" will be dealt with as "targets."
An American F18 Super Hornet shot down the plane after it dropped bombs near U.S.-backed forces near Raqqa, Syria.
Here are five things we know about the incident.
1. The plane, believed to be the first manned aircraft shot down since 1999 when the United States was flying missions over Kosovo, was a Syrian SU-22 fighter bomber. The SU-22 is a Russian variable-sweep wing plane, meaning the wings can be swept back and then returned to their original position during flight.
2. The Russian defense minister issued this warning:
"Any flying objects, including planes and drones of the international coalition, discovered west of the Euphrates River will be tracked as aerial targets by Russia's air defenses on and above ground."
3. The defense minister also said Russia will suspend coordination with the United States in Syria in the "de-confliction zone." A "hotline" for Russian and U.S. military officials to talk about activity within the zones was established in 2015.
4. The United States says it will continue to use the hotline.
5. The United States responded to the Russian warning by issuing this statement.
"The coalition does not seek to fight Syrian regime, Russian, or pro-regime forces partnered with them, but will not hesitate to defend coalition or partner forces from any threat."