According to The Wall Street Journal, researchers believe this week’s cyberattack on dozens of municipal water systems in the U.S. state of Minnesota was likely carried out by hackers linked to the Islamic Republic.

According to these sources, the hackers may have posed as hackers based in Iran in order to increase tensions between Iran and the United States, although intelligence experts have dismissed this scenario as unlikely.

Minnesota state officials say that after the attack, at least one city’s water wells and water treatment facilities were temporarily taken offline, and several other cities were forced to abandon their automated systems and switch to manual methods. Based on this report, so far there is no sign of contamination or of the drinking water in these areas becoming unsafe for consumption.