WASHINGTON — The FBI’s announcement that it recently came upon new emails possibly pertinent to the Hillary Clinton email investigation raised more questions than answers.

FBI Director James Comey said in a letter to Congress on Friday that the bureau had discovered the emails while pursuing an unrelated case and would review whether they were classified.

The announcement, vague in details, immediately drew both criticism and praise to Comey himself. Some questions and answers:

Where did the emails come from?

The emails emerged during a separate criminal sexting investigation into former Rep. Anthony Weiner, estranged husband of Huma Abedin, one of Clinton’s closest aides, a U.S. official with knowledge of the matter told The Associated Press. The official was not authorized to speak publicly about the investigation and discussed the matter on condition of anonymity.

Federal authorities are investigating communications between Weiner, a New York Democrat, and a 15-year-old girl.

It was not clear from Comey who sent or received the emails or what they were about.

Why is this coming out so close to the election?

Apparently because the emails were found very recently. In his letter to Congress, Comey said he had been briefed only Thursday by investigators.

Releasing the letter opened Comey to partisan criticism that he was dropping a significant development too close to an election. But keeping it under wraps until after Nov. 8 would surely have led to criticism that he was sitting on major news until after the election.

Comey has said there are no easy decisions on timing in the case. In an internal email sent Friday to FBI employees, he said he was trying to strike a balance between keeping Congress and the public informed and not creating a misleading impression, given that the emails’ significance is not yet known.

“In trying to strike that balance, in a brief letter and in the middle of an election season, there is significant risk of being misunderstood,” he wrote.

Is the disclosure standard for the FBI?

No, but neither was the Clinton email investigation.

In a nod to the extraordinary nature of an election-year probe into a presidential candidate, Comey promised extraordinary transparency as he announced the investigation’s conclusion in July.

“I am going to include more detail about our process than I ordinarily would, because I think the American people deserve those details in a case of intense public interest,” Comey said at the unusual news conference where he announced the FBI would not recommend criminal charges against Clinton.

Since then, the FBI has periodically released investigative files — that is, summaries of witnesses who were interviewed. Those materials aren’t typically public.

Comey, a Republican, has served in government under both Democratic and Republican administrations. He speaks repeatedly about the need for the FBI to be accountable to the public.

His letter Friday seemed in keeping with a statement he made to Congress last month, that although the FBI had concluded its investigation, “we would certainly look at any new and substantial information” that emerged.

But why was the letter so vague?

For one thing, the FBI avoids publicly discussing ongoing criminal investigations, or even confirming it has one open.

It also appears the FBI isn’t sure what it has. Comey said the FBI cannot yet assess whether the material is significant, or how long it would take to complete the additional work.

Nevertheless, the letter’s vagueness was immediately seized upon by critics as unacceptable and leaving the public in the dark.

What happens now? Does this increase the likelihood that someone could be charged?

The FBI will review the emails to see if they were classified and were improperly handled.

It’s impossible to say if anyone is in greater jeopardy than before.

The FBI announced in July that scores of emails from Clinton’s server contained information that was classified at the time it was sent or received. So, new emails determined as classified might do nothing to change the legal risk for anyone who sent them.

Comey said in July that the FBI had found no evidence of intentional or willful mishandling of classified information, of efforts to obstruct justice or of the deliberate exposure of government secrets. Those were elements that Comey suggested were needed to make a criminal case.

Nothing in the letter appears to change that standard.