The Israeli military said it shot down a Syrian warplane Tuesday after it entered Israeli airspace.
Israeli military spokesman Lt. Col. Jonathan Conricus said the Syrian Sukhoi fighter jet approached Israel at a "relatively high speed" before the Israeli military fired two Patriot interceptor missiles at the jet after it entered Israeli territory.
Syrian state media reported, however, the warplane was fired on as it participated in operations against rebels in Syrian territory.
"The Israeli enemy confirms its support for the armed terrorist groups and targets one of our warplanes, which was striking their groups in the area of Saida on the edge of the Yarmouk Basin in Syrian airspace," the official Syrian Arab News Agency quoted a military source as saying.
Lt. Col. Conricus said the plane "most likely" crashed in the southern part of the Golan Heights. It was not known if the plane intentionally entered Israeli airspace. He also said the pilot's fate was unknown.
Conricus said heightened activity near Israel's frontier with Syria put the military on "elevated alert." The increased activity has prompted Israel to issue a series of warnings to ensure the 1974 disengagement agreement between the two countries, which established a demilitarized buffer zone along the Golan Heights frontier, is enforced.
Israel seized the Golan Heights from Syria in 1967. The U.N. deployed a peacekeeping force there two years later.