Former US president Donald Trump says his Mar-a-Lago estate in Palm Beach, Florida, is being raided by FBI agents.
Mar-a-Lago "is currently under siege, raided, and occupied by a large group of FBI agents," Mr Trump said in a statement.
"They even broke into my safe."
The circumstances of the raid were not immediately clear, however Mr Trump's son Eric alleged the FBI raid concerned documents sought by the National Archives and Records Administration.
Armed police officers have been filmed outside of Mr Trump's Mar-a-Lago home, while his supporters have been seen waving pro-Trump flags from the footpath and from passing cars.
A Justice Department spokesperson declined to comment on the raid, including about whether Attorney-General Merrick Garland had personally authorised the search.
"After working and cooperating with the relevant Government agencies, this unannounced raid on my home was not necessary or appropriate," Mr Trump wrote.
Mr Trump made no mention of the raid during a tele-town hall appearance on Monday night while endorsing a Republican candidate for Tuesday's Senate primary election in his first public remarks since news of the search came to light.
On social media, however, the former president called the search a "weaponisation of the Justice System" and an "attack by Radical Left Democrats who desperately don't want me to run for President in 2024".
Despite this, the Biden administration has said it had no prior knowledge of the search.
And the current FBI director, Christopher Wray, was appointed by Mr Trump five years ago, serving as a high-ranking official in a Republican-led Justice Department.
The action marks a dramatic escalation in law-enforcement scrutiny of Mr Trump, and comes as he has been laying the groundwork to make another bid for president.
A person familiar with the matter told the Associated Press on condition of anonymity that agents were looking to see if Mr Trump had additional presidential records or any classified documents at the estate.
The Justice Department has been investigating the discovery of boxes of records containing classified information that were taken to Mar-a-Lago after Mr Trump left office.
That matter was referred to the Justice Department by the National Archives and Records Administration, which said it had found classified material in 15 boxes at the Florida mansion.
Federal law prohibits the removal of classified documents to unauthorised locations, though it is possible that Mr Trump could try to argue that, as president, he was the ultimate declassification authority.
Mr Trump has previously said he agreed to return certain records to the archives, calling it "an ordinary and routine process".
The US has multiple statutes governing classified information, including a law punishable by up to five years in prison that makes it a crime to remove such records and retain them at an unauthorised location. Another statute makes it a crime to mishandle classified records either intentionally or in a grossly negligent manner.
A separate investigation related to efforts by Mr Trump's allies to undo the results of the 2020 presidential election and the January 6 riot at the US Capitol has also been intensifying in Washington.
ABC/wires
