Two municipal water systems in New Jersey were targeted in cyberattacks widely thought to be the work of Iran, the state said Wednesday.
Minnesota systems may have been targeted by Iranian groups, U.S. officials say.
The US and Iran each fired barrages of missiles Thursday, as the pattern of back-and-forth strikes took hold again and hope dimmed for any quick resolution.
Jordan's air defenses intercepted five missiles launched from Iran early Wednesday, hours after the U.S. military said it had knocked down an Iranian missile barrage launched against American forces in the Middle East.
Iran publicly hanged two men on Tuesday who were convicted of killing four police officers during nationwide anti-government protests in January, state media reported.
Neither the U.S. nor Iran reported carrying out any attacks for three straight days - a respite after weeks of bombardments that led to fears of a return to all-out war.