Cyberattacks on U.S. water systems that officials suspect may be linked to Iran-backed hackers have been reported in at least a dozen states, sources familiar with the matter told CBS News on Wednesday. In Minnesota specifically, more than 30 community water systems were impacted, CBS News previously learned. So far, according to officials, the cyberattacks have had no impact on drinking water, which has remained safe. The water agencies were advised to disconnect their operating programs from the internet and strengthen their password protections and firewalls. While federal investigators suspect Iran-backed hackers are behind the attacks, they have not made any formal attribution.