Michigan has become the latest state to report cyberattacks targeting its water systems, joining Minnesota in what authorities describe as a growing threat to critical infrastructure across the United States.

Despite the breaches, officials in both states have assured the public that all affected systems remain operational and safe.

On Saturday, Michigan confirmed nine of its water systems had been impacted, following a federal cyber alert issued on Tuesday regarding attempts to tamper with operational technology at water facilities.

Dale George, communications director for the state’s Department of Environment, Great Lakes, and Energy, stated that Michigan received “a small number of reports from Michigan communities indicating activity consistent with what federal agencies described.”

He later specified nine systems were affected. George emphasized, “All systems continued to operate safely, issues were addressed by local operators, and there are no known impacts that posed a public health concern.”

Earlier in the week, Minnesota authorities disclosed that over 30 water systems in their state had been targeted by similar cyberattacks.

Minnesota IT Services reported on Thursday that no communities had requested residents to alter their drinking water usage.

The agency clarified that most confirmed attacks involved technology used for remote monitoring and control of equipment, and while malicious activity was confirmed, it did not mean every impacted community experienced water service disruption.

However, some localized disruptions did occur. For several hours on Monday, the city of Braham, located about 70 miles north of Minneapolis, asked residents to minimize water use after its water plant went offline.

A news release from the city of approximately 1,700 people attributed the outage to a cyberattack, which shut down the operating controls for the well and water treatment plant, leaving the city temporarily reliant on its water tower.

No issues with water quality were reported. In Plymouth, a city of about 80,000 outside Minneapolis, officials announced on social media that water infrastructure communications had been restored by Tuesday afternoon following a cyberattack.

The source of these attacks remains under investigation, though they coincide with warnings that Iranian hackers have been focusing on such systems. The FBI, which is leading the inquiry, has not publicly identified a culprit, with a spokesperson declining to comment on potential perpetrators on Thursday.

Last week, the FBI, Cybersecurity and Infrastructure Security Agency (CISA), and other agencies issued an advisory warning that Iranian hackers have been targeting water and wastewater systems, as well as operational controls in other critical infrastructure sectors. In a statement on Saturday, the FBI affirmed,

“The FBI is aware of recent public reporting around Water and Wastewater (WWS) sectors. The FBI and our interagency partners are fully engaged to protect critical infrastructure and we remain well-equipped to protect against cyber threats of all varieties.”

Digital warfare has become a significant component of modern military conflict, and local utilities such as water plants or healthcare facilities frequently lack the necessary funding and specialized expertise to implement advanced software patches or other robust security measures.

This inherent vulnerability makes them particularly attractive targets for malicious actors, both for the relative ease of penetration and the potential for widespread public panic caused by service disruptions.

Indeed, Iran’s interest in the operations of water systems inside the U.S. dates back years, with a group of Iranian hackers charged in 2016 by the Justice Department in connection with a cyberattack targeting a small dam near New York City.

The incidents have also drawn political commentary.

During a Cabinet meeting on Friday at the Camp David presidential retreat in Maryland, Donald Trump claimed without evidence that recent cyberattacks in Minnesota were the fault of the state, including Democratic Gov. Tim Walz.

Governor Walz responded on social media, stating that Trump “knows exactly who is responsible for this attack, and knows that other states were hit too.”