Sen. Ron Wyden's office tweeted in a series of messages Thursday that it was an "established fact" that President Trump had actively encouraged Russia "to attack our democracy."

The tweets from the Oregon Democrat's official Twitter account came in response to a Senate hearing featuring former FBI Director James Comey, who was fired Tuesday by Trump.

"I fear my colleagues are forgetting that Donald Trump urged the Russians to hack his opponent," one tweet said, adding a few seconds later, "The question is not whether Trump actively encouraged Russians & Wikileaks to attack our democracy. He did. That's an established fact."

"The only question is whether Trump, or someone associated with him, also coordinated with the Russian efforts," the account added.

The tweets were not by Wyden himself. In a tweet about 40 minutes prior, he said he was turning over his Twitter account to his office. "Those tweets were by press staff, echoing the statement he made in the Intelligence Committee just now," Wyden spokesman Keith Chu told the Washington Examiner.

The FBI investigation into Russia's involvement in the 2016 election has determined that hackers in the former Soviet Union broke into servers used by Hillary Clinton campaign manager and turned them over to WikiLeaks in an effort to boost Trump's bid. Evidence of direct involvement by anybody on the Trump campaign has not been found, though the FBI's probe is continuing.

Trump has repeatedly denied the accusations.

Russians also are believed to have targeted Republican and conservative sites.