Michigan officials on Saturday reported cyberattacks on nine of the state’s water systems, as investigators look into whether Iran is linked to a spate of similar hacks on states across the country.

The FBI is investigating after Michigan received a federal cyber alert Tuesday about attempts to tamper with the water systems’ operational technology. The development comes after Minnesota said it had suffered similar hacks on its water systems, with the cities of Plymouth and Braham being among the areas impacted.