Donald TrumpDonald John TrumpBiden slams Trump over golf gif hitting Clinton Trump Jr. declines further Secret Service protection: report Report: Mueller warned Manafort to expect an indictment MORE appeared to question Hillary ClintonHillary Diane Rodham ClintonBiden slams Trump over golf gif hitting Clinton Overnight Cybersecurity: Equifax hit by earlier hack | What to know about Kaspersky controversy | Officials review EU-US privacy pact Overnight Tech: Equifax hit by earlier undisclosed hack | Facebook takes heat over Russian ads | Alt-right Twitter rival may lose domain MORE's mental fitness for the presidency on Saturday, calling her "unstable" and saying she had suffered a "short-circuit in the brain."

The GOP presidential nominee jumped on Clinton's recent remarks that she had "short-circuited" when misspeaking about the FBI's probe into her email server.

"She short-circuited, she used the term 'short-circuited.' She took a little short-circuit in the brain," he said in Windham, N.H.

"She's got problems," Trump continued. " I mean, if we had real people, this would be a real problem for her."

"But I think that the people of this country don't want someone who will short-circuit up here. Not as your president," he added, pointing to his head.

Trump's comments were the latest in a series of sharp personal attacks against Clinton in recent days.

At a rally on Friday, Trump called Clinton a "monster" and "unstable."

"Unstable Hillary Clinton, lacks the judgment, temperament and moral character to lead this country — and I believe that so strongly," he told the audience at a Des Moines, Iowa, rally.

"She's really pretty close to unhinged, and you've seen, you've seen it a couple times. The people in the background know it, the people who know her know it and she's like an unbalanced person."

Earlier Saturday in a series of tweets, Trump also suggested that Clinton might be "brainwashed," citing her "short-circuited" remark.

"Crooked Hillary said loudly, and for the world to see, that she "SHORT CIRCUITED" when answering a question about her e-mails. Very dangerous!" he wrote. "Anybody whose mind "SHORT CIRCUITS" is not fit to be our president! Look up the word "BRAINWASHED."

A Trump video on Saturday also depicted Clinton as a short-circuiting robot.

Clinton sparked controversy earlier this week when she said the FBI director had concluded that she was "truthful" about classified information on the private email server she used when she was secretary of State.

FBI Director James Comey has said Clinton was truthful to the agency when it investigated the matter, but he has declined to say whether he believes she was truthful with the public. The FBI's conclusions contradicted a number of Clinton's claims about her email system.

Clinton on Friday said she had "short-circuited." She said her comments were only meant to mean that the FBI chief believed she was truthful when she spoke to the agency.