A mortar shell was fired from Syria toward the Israeli Golan Heights on Sunday, though no damage or injuries were caused, the army said.
The IDF said the projectile seemed to have been errant fire from fighting across the border.
Incoming rocket alert sirens in the area were not activated, as the shell appeared to be heading toward an open field, the Home Front Command said.
The military said it sent soldiers to search the area to determine if the shell actually reached Israeli territory or if it fell short of the border.
On Saturday, Arabic media reported that 12 Iranian military personnel had been killed in an alleged Israeli airstrike on an Iranian base in Syria the night before.
There has been no official confirmation of fatalities by either Syrian or Iranian authorities. There was also no immediate official Israeli comment. Israel does not, as a rule, comment on reported strikes in Syria.
Prime Minister Benjamin Netanyahu warned, in a video clip published Saturday night, that Israel would not tolerate an Iranian military presence in Syria.
Also on Friday, rebels shot down a Syrian regime helicopter in a region near Israel’s northern border, killing its two crew members, a monitoring group said.
Israel captured the Golan Heights from Syria in the 1967 Six Day War and later extended Israeli law to the area in a move never recognized by the international community.