The United States government has warned that Iranian state-backed hackers are actively breaching and disrupting industrial control systems used by American water and energy providers.

The alert comes months after federal agencies warned of increased cyberattacks by Iranian actors amid the ongoing war.

In an advisory updated Wednesday, the FBI, NSA, Department of Energy and CISA said Iranian hackers were targeting programmable logic controllers on internet-connected operational networks.

The attacks could allow hackers to manipulate data displayed by the systems, potentially causing outages and disrupting operations.

The agencies warned that “potentially all internet-exposed” industrial control systems could be vulnerable and urged critical infrastructure operators to take immediate action.

According to the advisory, the Iranian-backed hackers were “conducting this activity to cause disruptive effects within the United States,” likely in response to the ongoing conflict involving Iran, the U.S. and Israel.

The FBI said the hackers had breached at least one critical infrastructure provider and altered the programming logic of industrial controllers, disabling processes responsible for critical shutdowns and alarms.

This allowed systems to enter unsafe conditions without alerting operators to the anomalies, the agencies said.

This latest warning follows a series of cyberattacks by Iranian government hackers and affiliated groups across the region since the war began in February.