The number of US states affected by the recent hacking campaign targeting water and wastewater facilities continues to grow.

At least 12 states have been hit, according to ABC News, but the names of only a handful of the affected states are currently known.

States affected by water system cyberattacks

Minnesota was the first to report attacks, with more than 30 community water systems targeted on July 26 and 27. Michigan has also officially confirmed that a “small number” of communities have seen malicious cyber activity.

At least one city in South Dakota has also reported a cyberattack that appears to be part of the same campaign.