Breaking news: FBI to further investigate Hillary Clinton's emails

Democratic presidential candidate Hillary Clinton speaks with senior aide Huma Abedin aboard her campaign plane at Westchester County Airport in White Plains, N.Y., Friday, Oct. 28, 2016, before traveling to Iowa for rallies. (AP Photo/Andrew Harnik)

Democratic presidential candidate Hillary Clinton speaks with senior aide Huma Abedin aboard her campaign plane at Westchester County Airport in White Plains, N.Y., Friday, Oct. 28, 2016, before traveling to Iowa for rallies. (AP Photo/Andrew Harnik)

Update 3:52 p.m.: Hillary Clinton's campaign is now responding to FBI Director James Comey's letter to Congress. In a statement, Clinton campaign chairman John Podesta called on Comey to release more information immediately.

The director owes it to the American people to immediately provide the full details of what he is is now examining. We are confident this will not produce any conclusions different from the one the FBI reached in July."

Updates 2:51 p.m.:  Donald Trump's Georgia campaign is urging its surrogates not to publicly respond to the news.

Meanwhile, NBC's Pete Williams, widely regarded as one of the top law enforcement reporters on Capitol Hill is reporting that sources tell him there's more to this story than we know. A sample from his colleague on Twitter:

Original post:

With less than two weeks to go before the election, the FBI on Friday announced it is investigating new developments in the Hillary Clinton email case.

In a letter to congressional leaders, FBI Director James Comey said details found in an “unrelated case” led to the discovery of "emails that appear to be pertinent to the Clinton investigation.”

Comey indicated that he had been briefed on the new material yesterday. "I agreed that the FBI should take appropriate investigative steps designed to allow investigators to review these emails to determine whether they contain classified information, as well as to assess their importance to our investigation," he wrote.

The FBI had previously closed its investigation in July with no charges, though Comey had concluded there had been classified content exchanged on the server and that Clinton had been "extremely careless."

Rest assured, this will dominate the next few days of campaign coverage. Clinton's campaign hasn't responded to the news yet. We'll update you with more when they do.

Donald Trump was campaigning New Hampshire Friday when he received the news. His reaction, via Politico:

He continued, "I have great respect for the fact that the FBI and the department of justice are now willing to have the courage to right the horrible mistake that they made."

Trump campaign manager Kellyanne Conway gave a first impression on Twitter:

Comey, in his letter, said the FBI does not yet know whether the new information is significant or how long it would take to complete the new investigation.

House Speaker Paul Ryan of Wisconsin appears to be first out with a response, saying Clinton "has nobody but herself to blame."