The FBI on Thursday conducted a court-authorized search of former national security adviser John Bolton's Maryland home as part of a national security investigation, according to people familiar with the matter. Agents were seen entering the residence in Bethesda early in the morning, with between four and six FBI personnel observed by reporters.

"The FBI is conducting court authorized activity in the area. There is no threat to public safety," an FBI official told NBC News, declining to comment directly on Bolton. A person familiar with the operation said the search was related to classified records.

Bolton, reached by CNN, said he was unaware of the search and was "looking into it further." The FBI has not confirmed what investigators were seeking, and the agency declined to elaborate beyond its public safety statement.

FBI Director Kash Patel posted on X shortly after 7 a.m. ET, the time agents reportedly arrived at the home: "NO ONE is above the law... @FBI agents on mission." Attorney General Pam Bondi amplified the message, writing, "America's safety isn't negotiable. Justice will be pursued. Always." Patel's deputy director, Dan Bongino, added in his own post: "Public corruption will not be tolerated."

The New York Post first reported the raid. The outlet said Patel himself ordered the investigation into Bolton, citing a Trump administration official.

The search follows years of tension between President Donald Trump and his former adviser. Trump fired Bolton in 2019 and later moved to terminate his Secret Service protection hours after beginning his second term in January. Trump has repeatedly derided Bolton, saying this month that the media was "constantly quoting fired losers and really dumb people like John Bolton."

Bolton angered Trump after publishing his 2020 memoir The Room Where It Happened, which portrayed the president as uninformed and focused on personal image. The book alleged Trump sought help from foreign leaders in Ukraine and China to influence the 2020 election. The Justice Department under Trump sued to block its publication, calling it "a flagrant breach" of Bolton's security obligations. That lawsuit was dropped in 2021 after President Joe Biden took office.

The Justice Department also investigated whether Bolton unlawfully disclosed classified information in the memoir, but Biden-era officials closed the inquiry. Trump, however, has intensified efforts in his second term to pursue political adversaries, opening probes into figures ranging from New York Attorney General Letitia James to former Rep. Adam Schiff.

Bolton, a longtime Republican foreign policy hawk, previously served as U.S. ambassador to the United Nations under President George W. Bush. The raid marks the most aggressive action yet taken against him since Trump's return to office.