Israel resorted to air strikes inside Syria after an attack from across the border killed a teenager and left two injured in Golan Heights.
Israel targeted nine military areas including a headquarters, in Syria.
The attacks were triggered by the death of a teenager in an explosion at a construction site in Golan on Sunday; the boy was accompanying his father to the site when the explosion occurred.
The boy's father, a defence contractor, was injured in the incident.
Prime Minister Benjamin Netanyahu said, "The enemies of the state of Israel use all means, they don't hesitate to attack civilians and kill children. They do not differentiate between Israel's Jewish and non-Jewish citizens."
Israel military spokesman Lt Col Peter Lerner called the attack an 'unprovoked act of aggression' against Israel, and a direct continuation to recent attacks that occurred in the area.
"The IDF will not tolerate any attempt to breach Israel's sovereignty and will act in order to safeguard the civilians of the state of Israel," Lerner said.
It is not yet known if Sunday's explosion occurred due to a rocket, mortar round or tank fire.
Golan is a disputed region captured by Israel from Syria in 1967 after the Six-Day War.
Sunday's explosion and the subsequent air strikes are the biggest clash between the two countries in the last three years since the Syrian conflict began.
In March, Israel carried out air strikes on Syrian military targets after an IED explosion killed four of its soldiers in Golan.
Image: Golan is a disputed region captured by Israel from Syria in 1967. Photo: courtesy of David Shay.