A mortar shell landed on the Israeli side of the Golan Heights on Sunday evening, causing no injuries but starting a brush fire.
Firefighters scrambled to the scene to deal with the blaze, the IDF said.
Israeli forces responded by firing three missiles at Syrian military targets, Channel 10 news reported. There were no reports of injuries from the missile strikes.
Security forces did not indicate if the bomb was deliberately fired at Israeli territory or if it was stray shot between the warring sides in Syria.
A number of projectiles fired from Syria have hit Israel over the last several years, as well as small arms fire. Israel has responded in the past with artillery fire.
Israel is currently in the midst of a major operation to stop Gazan rocket fire, but on Saturday night, a second front opened with Lebanon after two rockets landed near the town of Nahariya on the northern border.
The IDF responded with artillery fire towards the source of the launch.
It was the second time rockets were launched out of Lebanon at Israel since the beginning of Operation Protective Edge six day ago. There were no reports of damage or injuries in the attacks.
In the wake of the rockets from Lebanon, cities and towns in the north of the country decided to open their public bomb shelters and prepare them for use.
Last month, Israeli jets struck nine targets in Syria in response to an attack on a civilian vehicle inside Israel. A teenage boy was killed and two others were injured after an anti-tank missile was fired at their vehicle from within Syria.