The nearly two dozen top secret emails held on Hillary Clinton’s private, unsecured server reportedly contain "operational intelligence" that could offer information about U.S. intelligence collection and sources.

Fox News, citing an anonymous U.S. government official who has viewed the emails, reported that the presence of the operational intelligence on Clinton’s personal server endangered "sources, methods, and lives."

The State Department confirmed the top secret classification of 22 Clinton emails last Friday, announcing that it would not release the messages because of their highly sensitive nature.

"The documents are being upgraded at the request of the intelligence community because they contain a category of top secret information," State Department spokesman John Kirby said Friday.

This marked the first time that the State Department acknowledged that Clinton’s server held top secret communications. Previously, the agency had disputed the intelligence community inspector general’s finding that at least two messages contain top secret information, arguing that the material may have been overclassified.

Clinton’s presidential campaign argued Friday that the 22 emails were overclassified, demanding their release. Clinton has repeatedly claimed that she never sent nor received information marked classified on her personal email.

This is overclassification run amok. We adamently oppose the complete blocking of the release of these emails. https://t.co/77s6mtm0JA — Brian Fallon (@brianefallon) January 29, 2016

"This is overclassification run amok. We adamently oppose the complete blocking of the release of these emails," Clinton campaign spokesman Brian Fallon wrote on Twitter.

The top secret messages that the Obama administration blocked from release amount to seven email chains, or 37 pages. The State Department said last week that its Diplomatic Security and Intelligence and Research bureaus were looking into whether the information contained in the emails was classified at the time they were sent or received.

The latest revelation comes just as Clinton and her competitors for the Democratic nomination for president face off in the Iowa caucus. Recent polls have forecasted a tough battle between Clinton and Sen. Bernie Sanders (I., Vt.), who leads the former secretary of state by a wide margin in the second voting state, New Hampshire.

A spokesman for the Republican National Committee said Monday that Clinton appears dishonest and reckless in the wake of the new report.

"Not only did Hillary Clinton put lives at risk by exposing ‘Top Secret’ operational intelligence on her secret server, her claim that these emails were merely forwards of a news article looks even more dubious," RNC spokesman Michael Short said in a statement.

"With each damaging revelation, the level of Hillary Clinton’s dishonesty and recklessness just keeps getting worse."