Authorities were working Thursday to find the source of cyberattacks that targeted over 30 water systems in Minnesota and came amid warnings that Iranian hackers have been focused on such systems. Iran’s interest in the operations of water systems inside the U.S. dates back years. The state agency said most of the confirmed attacks involved technology that water systems use to remotely monitor and control equipment. It said that being impacted meant investigators confirmed there was malicious activity involving the system’s technology and didn’t mean every impacted community had their water service disrupted. That left the city for a time only able to provide residents with the water held in the water tower.