A suspected Iranian cyber attack likely set off rocket-warning sirens in the cities of Jerusalem and Eilat on Sunday, Israeli media reported on Monday.

Israeli cybersecurity authorities said the attack targeted municipal alert systems, but did not breach essential IDF infrastructure, according to Ynet

Authorities “instructed local councils to take precautionary steps to secure their alert systems, since they were activated by municipal alert systems and not by the IDF’s Home Front Command,” the report said.

The report cited Yoram Cohen, head of the Israel Internet Association, as saying that the hack “did not appear to harm any vital infrastructure,” but that it had once again exposed vulnerabilities in civilian systems.

“There is a gap between Israel’s excellent cyber defenses on critical infrastructure compared to non-critical civilian systems,” said Cohen. “This was not the first cyberattack to demonstrate the gap, and there must be increased awareness of the fact in order to protect Israel’s networks.”

Last week, the Checkpoint cybersecurity firm said Iranian hackers were likely behind a breach of email accounts belonging to former and current senior Israeli officials, including an Israeli ambassador to the United States and a former general.