The Israeli army said the mortars appeared to be errant fire from Syrian factions fighting each other across the border.
The Israeli Air Force on Saturday carried out an airstrike on positions of the Syrian regime's army forces at the Syrian side of the Golan Heights, local sources reported.
Israel said 10 projectiles from inside Syria had hit the Golan, the border area between Syria and Israel. It has responded in the past with limited strikes when fire has spilled into Israel. The IDF has conducted several night air raids on Syrian targets that it claimed were weapons systems being shipped to Lebanon by the militant Hezbollah group, which supports Damascus.
Syrian state media said a number of people were killed.
The Syrian Observatory for Human Rights, a Britain-based monitor which has been reporting on Syria's six-year-war, said two Syrian soldiers were killed in the Israeli strike. "As far as we are concerned, the Assad regime is responsible for what is happening in its territory and it will continue to bear the consequences if such events repeat themselves".
Aerial video footage released by the Israeli military purporting to show the strikes showed a machine gun and two tanks targeted and hit.
"We have no intention of allowing the breech of our sovereignty and harming of our security to go unpassed", said Israeli Defense Minister Avigdor Lieberman.
Around 510 square kilometres of the Golan are under Syrian control.
"Several projectiles fired from Syria hit an open area in the northern Golan Heights".