Hillary Clinton has lashed out at the FBI for releasing a letter advising that the bureau was investigating more of her emails so close to the election, describing it as “deeply troubling” and “pretty strange”.

FBI director James Comey on Friday (local time) announced in a letter to Congress that the bureau had come upon new emails possibly pertinent to an investigation into Mrs Clinton’s use of a private email system while she was secretary of state.

At a rally in Florida, the Democratic presidential nominee joined her campaign chairman and manager in calling for the FBI to release more details on the inquiry, which was reignited via an unrelated probe into Anthony Weiner, the disgraced former New York congressman who is separated from longtime Clinton aide Huma Abedin.

Trump insists Clinton is not to be trusted with the presidency. Photo: Getty

“I’m sure that some of you may have heard about a letter that the FBI director sent out yesterday,” Mrs Clinton told the crowd.

“Well, if you’re like me, you probably have a few questions about it. It’s pretty strange to put something like that out, with such little information, right before an election.

“In fact, it’s not just strange, it’s unprecedented, and it is deeply troubling, because voters deserve to get full and complete facts.

“And so, we call on director Comey to explain everything right away, put it all on the table.”

Trump: Clinton’s ‘criminal action was wilful, deliberate’

Mrs Clinton’s campaign manager John Podesta said earlier there was no indication the newly-discovered emails were connected to the Democratic nominee.

He said Mr Comey’s information was “long on innuendo” and “short on facts”, and that there was: “No evidence of wrongdoing. No charge of wrongdoing. No indication this is even about Hillary”.

Republican nominee Donald Trump reacted with glee to the renewed investigation, devoting a large part of a campaign speech in Colorado to attacking Mrs Clinton.

He said she was not to be trusted with the presidency.

“Her criminal action was wilful, deliberate, intentional and purposeful,” Mr Trump said.

“Hillary set up an illegal server for the obvious purpose of shielding her illegal actions from public disclosure and exposure.”

But Mrs Clinton said Mr Trump was “making up lies” about the situation.

“He is doing his best to confuse, mislead and discourage the American people,” she said.

“I think it’s time for Donald Trump to stop fear mongering, to stop disgracing himself, to stop attacking our democracy.”