Syrian rebels said a Russian Sukhoi Su-25 ground attack aircraft was shot down in rebel- and Hayat Tahrir al-Sham-held Idlib province.
According to reports and videos released online the aircraft was hit near near Saraqib, east of Idlib city, and later crashed.
The Russian ministry of defense confirmed the aircraft was shot down while flying in the Idlib de-escalation zone, Sputnik reported. After reviewing preliminary information, the ministry believes the aircraft may have been shot down using a man-portable air-defense missile system (MANPADS).
It is unknown which faction shot down the aircraft.
Free Syrian Army faction Jaysh al-Nasr released a video, saying the aircraft was shot down near Maasaran, 15km (9.5 miles) south of Saraqib.
The pilot reportedly ejected from the aircraft before it crashed. Other sources published video which they said showed the body of the pilot.
The Russian ministry of defense said the pilot ejected successfully but was later killed in a battle, Tass reported. It said the bailout occurred in an area controlled by Jabhat al-Nusra, the dominant jihadist faction in Hayat Tahrir al-Sham.
Pro-rebel media released video of the burning wreckage of a jet aircraft with a clearly Russian roundel on the wing.
Pro-Syrian government sources said that cruise missiles were launched from Russian ships in the Mediterranean Sea in response. These reports have not yet been confirmed.
The Su-25 is a single-seat twin-engine ground attack aircraft designed to provide close air support. It went into series production in 1978.
On March 16, 2016, Tass reported that over the previous six months, Russian Su-25s had performed over 1,600 sorties in Syria, dropping 6,000 bombs.