WASHINGTON — FBI Director James Comey in a letter to senior lawmakers Friday said the bureau would be reviewing additional emails from Hillary Clinton's private email server "to determine whether they contain classified information," a potentially significant development in the closing days of a presidential campaign that the Democratic nominee had appeared to be putting away.

In the letter explaining his decision to reopen the investigation, Comey said "the FBI cannot yet assess" whether the information is "significant" nor could he offer a timetable for how long it will take investigators to make an assessment.

Comey wrote that the discovery of additional messages had occurred "in connection with an unrelated case," leading to the decision to reopen the probe.

Responding shortly during a speech in New Hampshire, Republican presidential nominee Donald Trump gleefully discussed the "breaking news announcement."

"Hillary Clinton's corruption is on a scale we have never seen before," Trump said, and her "criminal scheme" should not be allowed in the Oval Office.

"Perhaps justice will be done," the GOP nominee said of the development.

In July, Comey announced that while Clinton and her aides while she was secretary of State had been "extremely careless" in the way they'd handled classified information, he recommended that no criminal charges be filed.

Soon after, the director testified before skeptical GOP lawmakers to explain the bureau's recommendation, which had been adopted by Attorney General Loretta Lynch.

“We’re mystified and confused by the fact pattern you laid out and the conclusion you reached," House Oversight Committee Chairman Jason Chaffetz, R-Utah, told Comey.

Comey, however, was unequivocal in maintaining that the conclusions of investigators were not a close call.

“There is no way anybody would bring a case against John Doe or Hillary Clinton for the second time in 100 years based on those facts," he told the House panel on July 7.

The news of the FBI's new inquiry comes just 11 days before Americans go to the polls in an election where Clinton had opened up a significant lead against Republican Donald Trump.

Trump has cited the closed FBI inquiry as evidence that the election was "rigged" against him, and at a recent debate said that, if he's elected president, he would appoint a special prosecutor to investigate Clinton.

Following Comey's announcement Friday, House Speaker Paul Ryan in a statement said, "Hillary Clinton has nobody but herself to blame."

"This decision, long overdue, is the result of her reckless use of a private email server, and her refusal to be forthcoming with federal investigators," Ryan said, adding that he was again calling for Clinton to no longer receive classified briefings, a traditional courtesy afforded major-party presidential nominees.

House Judiciary Committee Chairman Bob Goodlatte, R-Va., in a statement said the decision " reinforces what the House Judiciary Committee has been saying for months: the more we learn about Secretary Clinton’s use of a private email server, the clearer it becomes that she and her associates committed wrongdoing and jeopardized national security."

Meanwhile, Trump's campaign manager, Kellyanne Conway, wrote on Twitter that "a great day in our campaign just got even better."

In his New Hampshire speech, Trump suggested the rest of his campaign message for the day would no longer matter as much.

"The rest of my speech is going to be so boring," he joked.