Michigan has disclosed cyberattacks on nine of its water systems, joining Minnesota, which reported breaches at 30 sites earlier in the week, as the FBI investigates what US authorities say are incidents affecting at least seven states. No culprit has been formally identified, but the attacks follow a joint advisory from the FBI and the Cybersecurity and Infrastructure Security Agency (CISA) warning that Iranian hackers had been targeting water and wastewater systems and other critical infrastructure. Michigan officials said all affected systems continued to operate safely, while Minnesota authorities noted that the breaches did not result in water supply disruptions for residents.