President Trump says US Navy will begin blockade of Strait of Hormuz

Iranian-affiliated cyber actors are targeting U.S. critical infrastructure, according to a new warning from the federal government.

Numerous agencies, including the FBI and NSA, "are urgently warning U.S. organizations of ongoing cyber exploitation of internet-connected operational technology (OT) devices, including Rockwell Automation/Allen-Bradley-manufactured programmable logic controllers (PLCs), across multiple U.S. critical infrastructure sectors," according to an alert published on Tuesday.

Multiple critical infrastructure sectors experienced disruptions, and in some cases "this activity has resulted in operational disruption and financial loss," the alert said.

The Iranian-backed group has targeted government services industry, water and wastewater systems and the energy sector, according to the agencies.

Iranian-backed actors have carried out similar actions in the past, according to the government.

-ABC News' Luke Barr

Kuwait's Ministry of the Interior is urging residents to stay indoors from midnight until 6 a.m. on Wednesday as a "precautionary measure."

The ministry said the advisory is being issued "as a precautionary measure aimed at safeguarding everyone's safety, strengthening the level of prevention, and enabling security authorities to perform their duties with high efficiency."

The U.S. carried out strikes against approximately 50 military targets on Kharg Island on Tuesday that had previously been struck last month, according to a U.S. official.

In mid-March, the U.S. struck 90 military targets on the island, which is Iran’s oil transportation hub. Those 90 targets were described then as including storage bunkers for naval lines and missiles, and other military infrastructure.

The island itself is roughly the same size as Key West, Florida, or a third the size of the island of Manhattan.

-ABC News' Luis Martinez

Israel is "crushing" the Iranian regime "with increasing force," Israeli Prime Minister Benjamin Netanyahu said in a statement Tuesday.

“Yesterday we destroyed transport planes and dozens of helicopters, and today we attacked the railroads and bridges used by the Revolutionary Guards," Netanyahu said.

"Yesterday our pilots destroyed transport planes and dozens of helicopters at an Iranian air force base. Today they attacked the railroads and bridges used by the Revolutionary Guards," Netanyahu added. "They use them to transport raw materials for weapons, weapons, and the activists who attack us, the U.S. and the countries of the region."