The Israeli military said it "views this event with great severity and remains prepared for a wide variety of scenarios."
About 20 projectiles were fired into the Israeli-occupied Golan Heights by Iranian forces on Thursday, but minimal damage was reported and there were no Israeli casualties, Israel's military said.
The rockets targeting Israel Defense Forces forward posts in the Golan Heights were fired around 12:10 a.m. Thursday local time (5:10 p.m. Wednesday ET), Lt. Col. Jonathan Conricus told reporters.
The Israeli military said the rockets were fired by Iran's Quds Force, which is part of Iran's Revolutionary Guards.
A number of rockets were intercepted by the Israeli Army's Iron Dome aerial defense system, the army said on Twitter. "The IDF views this event with great severity and remains prepared for a wide variety of scenarios."
Conricus said, "Israel has responded to this attack and this is an ongoing situation."
Syria's state media said Syrian air defenses had intercepted "hostile Israeli missiles" early Thursday that were fired over southwestern Damascus, The Associated Press reported.
The reported rocket fire comes a day after President Donald Trump announced that the United States will withdraw from the Iran nuclear deal, a move strongly supported by Israeli Prime Minister Benjamin Netanyahu. It is unclear if the reported rocket fire is related.
The Israeli military did not say where the rockets were fired from. The Golan Heights borders Syria, which is embroiled in a years-long civil war and where Iranian forces are alleged to be operating.
Israel is believed to have bombed an air base in Syria on April 9, which Iranian state media reported killed seven Iranian military personnel.
Israel has struck inside Syria more than 100 times since 2012 — mostly targeting suspected weapons convoys for Hezbollah, the Lebanese militant group whose fighters are in Syria backing the regime of President Bashar al-Assad.
In February, Israel's military shot down an Iranian drone that it said entered Israeli airspace and was launched from Syria. Israel's military said it launched a "large-scale attack" in response against Iranian targets in Syria.
Israel is increasingly wary of Iran's influence in Syria, three U.S. officials have told NBC News. While Russia runs the air war for the Assad regime, Iran is now running the ground war, the officials said, with Iranian military present at every major Russian and Syrian government base in the country.
Israel's military went on high alert Tuesday and bomb shelters were ordered open in the Golan Heights following reports of "irregular activity" of Iranian forces in Syria, according to the AP. After an uneventful night, the military on Wednesday called on residents to return to "full civilian routine," meaning studies and excursions would continue as usual, although the shelters would remain open.