President Donald Trump on Saturday accused The New York Times of a “virtual act of treason” for publishing a story about U.S. digital incursions into Russia’s electrical power grid as part of an effort to battle the Kremlin’s cyber warfare.

He also tweeted that the story wasn’t true, wrapping up by calling the media “cowards” and the, as he so often does, “enemy of the people.”

Current and former U.S. officials told the Times about the deployment of American computer code into Russia’s electrical power grid and other targets both as a warning to the Kremlin and as a readied strike in case of a Russian cyberattack.

The Times responded to Trump’s attack by saying that “accusing the press of treason is dangerous.”

It cited his administration’s own officials as saying they had “no national security concerns” about the story, which was “perhaps an indication that some of the intrusions were intended to be noticed by the Russians.”