Sen. Dianne Feinstein (D-Calif.) said Sunday she believes an obstruction of justice case is beginning to form against President Trump in the investigation into Russian interference in the 2016 presidential election.

“The [Senate] Judiciary Committee has an investigation going as well and it involves obstruction of justice and I think what we’re beginning to see is the putting together of a case of obstruction of justice,” Feinstein said on NBC’s “Meet the Press.” “I think we see this in the four indictments and pleas that have just taken place, and some of the comments being made. I see it in the hyper-frenetic attitude of the White House, the comments every day, the continual tweets,” she added.

“I see it most importantly in what happened with the firing of Director Comey, and it is my belief that that is directly because he did not agree to lift the cloud of the Russia investigation. That’s obstruction of justice,” she continued, referring to former FBI Director James Comey.

{mosads}Feinstein is the ranking Democrat on the Senate Judiciary Committee, which is one of multiple congressional committees investigating Russian meddling in the election.

Former national security adviser Michael Flynn pleaded guilty on Friday to lying to federal investigators about his conversations during the presidential transition with the Russian ambassador to the U.S. about sanctions related to the Kremlin’s election interference.

Flynn is the fourth individual to plead guilty or be indicted by special counsel Robert Mueller in his ongoing probe into possible ties between Russia and the Trump campaign. Former Trump campaign chairman Paul Manafort and his associate Richard Gates were indicted in October. Former Trump campaign adviser George Papadopoulos, meanwhile, pleaded guilty to lying to the FBI.

Trump has repeatedly insisted the indictments and guilty pleas do not indicate any evidence of collusion between his campaign and Russia.

Trump earlier Sunday also lashed out on Twitter, saying the bureau’s reputation is “in Tatters” due to Comey’s leadership. Trump fired Comey in May.

“I’ve been here for 25 years now. There is a kind of instability, unpredictability; it’s one issue after the other. We’ve got major problems in the world with our allies now,” Feinstein said Sunday.

“And I think that this president is just precipitating more and more angst that’s going to lead to serious discord,” she added.

— This report was updated at 11:57 a.m.