Nine former FBI agents who investigated President Donald Trump and his alleged mishandling of classified documents after he left office following his first term filed suit against the FBI and Justice Department on Thursday alleging they were unlawfully terminated solely for their role in the probe.

The nine agents, who in the suit say they collectively count "over a century" of experience in the bureau on cases spanning from the Boston Marathon bombing to the first assassination attempt targeting President Trump, say they were all fired over the course of two days in February this year by FBI Director Kash Patel.

"Plaintiffs were unlawfully terminated not for any cause or any legitimate reason, but only to satisfy the President's personal vendetta," said attorney Abbe Lowell in the lawsuit filed Thursday in D.C. District court. "The firings did not follow any internal investigation or disciplinary process within the FBI, and Plaintiffs were not given any notice, a hearing, or an opportunity to appeal." The lawsuit, which seeks to have the agents' employment reinstated, points to public statements from Patel and Attorney General Todd Blanche, who the agents claim smeared their character by defending the firings.

"For example, a month after Plaintiffs' unlawful firings, Blanche stated that the Administration had 'cleaned house' at the FBI by firing anyone associated with investigations relating to Trump, and that there 'isn't a single man or woman with a gun, federal agent, still in that organization that had anything to do with the prosecution of President Trump,'" the suit claims.

The agents also argue that the firings may have endangered active counterintelligence and terrorism cases that some of the agents were involved in when they were terminated.

"As a result of their unlawful and hasty firings, Plaintiffs' investigations were not properly transferred to other FBI Special Agents or Analysts," the lawsuit says. "The impact of these heedless actions on America's national security is immeasurable." Each of the agents contend in the lawsuit that none volunteered for their assignment on the classified documents case against President Trump that resulted in his indictment on 42 counts of unlawfully retaining classified records after leaving the White House in 2021. Prosecutors said he repeatedly refused to return hundreds of documents containing classified information and took steps to thwart the government's efforts to retrieve them.

Trump, who pleaded not guilty to all charges, has long denied any wrongdoing, and the federal judge who oversaw the case ultimately dismissed it on the grounds that special counsel Jack Smith, who led the probe, was not lawfully appointed to his position.

In a statement responding to ABC News' inquiry about the lawsuit, a DOJ spokesperson said the department "is committed to treating employees fairly and complying with the law, and will continue to defend the President's authority to support and defend the nation." "Central to his Constitutional authority, the President is not required to delineate cause for federal employees who are removed," the spokesperson said. "To establish a standard of review would subject Presidential power to the whims of an outside agency or another branch of government, which is inappropriate."