President Donald Trump escalated his war on Robert Mueller on Thursday, slamming the special counsel investigation in a series of tweets as a "total mess" that has "gone absolutely nuts."

"The inner workings of the Mueller investigation are a total mess. They have found no collusion and have gone absolutely nuts," Trump wrote in one of five tweets blasting the special counsel.

"They are screaming and shouting at people, horribly threatening them to come up with the answers they want. They are a disgrace to our Nation and don't...care how many lives they ruin," he added.

Trump did not provide any evidence for his claims. The attacks come shortly after Trump forced out Attorney General Jeff Sessions, who had recused himself from the investigation, and named Matt Whitaker as acting attorney general. Whitaker is now overseeing Mueller.

The inner workings of the Mueller investigation are a total mess. They have found no collusion and have gone absolutely nuts. They are screaming and shouting at people, horribly threatening them to come up with the answers they want. They are a disgrace to our Nation and don’t... — Donald J. Trump (@realDonaldTrump) November 15, 2018

....care how many lives the ruin. These are Angry People, including the highly conflicted Bob Mueller, who worked for Obama for 8 years. They won’t even look at all of the bad acts and crimes on the other side. A TOTAL WITCH HUNT LIKE NO OTHER IN AMERICAN HISTORY! — Donald J. Trump (@realDonaldTrump) November 15, 2018

The expressions of public anger also comes after reports this week that the president has been stewing inside the White House, angry at staff and world leaders and seemingly deeply unhappy with the course of events.

Other Trump tweets Thursday morning questioned why Hillary Clinton is being protected, charged that Mueller and his "gang of Democratic thugs" had ruined lives, and accused Google, Facebook and Twitter of bias in favor of Democrats — what the president called "the real collusion."

Later Thursday, House Minority Leader Nancy Pelosi, D-Calif., ripped Trump over his tweets, saying that he "continues to wage an all-out campaign to obstruct the Mueller investigation."

Pelosi also said Trump installed Whitaker "for one purpose — to end the investigation."

Just hours before Trump's initial tweets, Vice President Mike Pence had a different take on the Mueller investigation in an exclusive interview with NBC's Vaughn Hillyard at the ASEAN Summit in Singapore.

"I think the people can be confident that we'll continue to cooperate, but they can also be confident that we're going to continue to focus on the issues that matter most to them," Pence said.

For much of the two months prior to Election Day, Mueller's probe into Russian electoral interference and possible ties between Trump's campaign and Moscow went largely quiet — as had been expected — due to Department of Justice guidelines that recommend not taking any law enforcement actions within 60 days of an election to avoid influencing voters or giving the appearance of swaying them.

And during that time period, with no public developments on the Mueller front, Trump stayed largely quiet on the issue, too. But with midterms now in the rear view mirror, Trump's has criticism has resumed.

On Tuesday, NBC News, citing a source familiar with the matter, reported that Trump's legal team was nearing completion of written answers to questions posed by Mueller that may be submitted as early as this week. The answers will pertain only to matters relating to Russian interference in the 2016 election, not obstruction of justice, the source said.

Earlier this month, NBC News and The New York Times reported on how longtime Trump associate Roger Stone and right-wing conspiracy theorist Jerome Corsi have found themselves at the center of the investigation.

NBC News reported that Mueller's office obtained communications that suggested Corsi, whom Mueller subpoenaed in September, may have had advance knowledge that emails from Hillary Clinton's campaign chairman John Podesta were stolen and provided to WikiLeaks.