Lansing, Michigan - Six people have been charged for plotting to kidnap Michigan governor Gretchen Whitmer, the FBI announced on Thursday. A further seven, all members of a militia group, are also in custody.

The FBI became aware of the plot by monitoring social media channels, where individuals claimed that certain state governments were violating the US constitution, according to an affidavit.

"Several members talked about murdering 'tyrants' or 'taking' a sitting governor. The group decided they needed to increase their numbers and encouraged each other to talk to their neighbors and spread their message," authorities said.

The FBI also noted that four of the six men had planned to meet on Wednesday to "make a payment on explosives and exchange tactical gear."

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The court filing claims that the conspirators also conducted surveillance at Whitmer's vacation home and discussed kidnapping in order to put her on "trial" for treason.

The plots were thwarted after several members of the group became FBI informants. The men charged were caught on tape planning the details of the governor's kidnapping, and discussing "the need for the government to collapse because it has become so tyrannical."

In one conversation caught on tape, the men complained that the governor had closed the state's gyms in response to the ongoing coronavirus pandemic.

During the same conference, Michigan Attorney General Dana Nessel announced additional charges against seven individuals linked to the militia group Wolverine Watchmen and its associates.

The men are all in custody and are charged under Michigan's anti-terrorism law.

"The individuals in custody are suspected to have attempted to identify the home addresses of law enforcement officers in order to target them, made threats of violence, intended to instigate a civil war, and engaged in planning and training for an operation to attack the capitol building of Michigan, and to kidnap government officials, including the governor of Michigan," Nessel said.

Speaking during a press conference on Thursday following the announcement of the charges, Michigan's governor called for national unity as the country continues to battle the coronavirus.

She also criticized President Donald Trump (74) for his approach to the virus, and for his unwillingness to denounce extremist groups like the one that plotted to kidnap her.

"Just last week, the president of the United States stood before the American people and refused to condemn white supremacists and hate groups like these two Michigan militia groups," Whitmer said.

She also criticized Trump for spending the last seven months "denying science, ignoring his own health experts, stoking distrust, fomenting anger, and giving comfort to those who spread fear and hatred and division."

Late on Thursday Trump responded to the alleged kidnapping plot by accusing Whitmer of doing a "terrible job."

"I do not tolerate ANY extreme violence," Trump tweeted. "Governor Whitmer – open up your state, open up your schools, and open up your churches!" He also again shifted attention to the ongoing protests against racial injustice, complaining that presidential candidate Joe Biden and the Democratic party "refuse to condemn" what he calls as "Looters and Mobs that burn down Democrat run cities."

The chair of Michigan's Republican Party, Laura Cox, thanked the FBI and local law enforcement for their work to stop the kidnapping in a statement Thursday.

"We live in a nation where we settle our political disagreements at the ballot box, not through violence, and any attempt to do otherwise is an attack on our Constitution, our values, and our American way of life," Cox said.