Hackers backed by the Chinese government are targeting U.S. water treatment plants and electrical grids, strategically positioning themselves within critical infrastructure systems to “wreak havoc and cause real-world harm to American citizens and communities,” FBI Director Christopher Wray is expected to tell  Congress Wednesday.

There has been far too little public focus on the fact that PRC hackers are targeting our critical infrastructure,” Wray will warn the House Select Committee on the Chinese Communist Party, according to excerpts of his remarks obtained by CBS News. “The risk that poses to every American requires our attention — now.”

The head of the FBI and other national security officials — including Jen Easterly, who leads the Cybersecurity and Infrastructure Security Agency — are scheduled to testify at a congressional hearing focused on the cybersecurity threat posed by China’s government.