The US justice department (DoJ) has asked a court to unseal the search warrant the FBI received before searching the Florida estate of Donald Trump, Merrick Garland said on Thursday.

The attorney general cited the “substantial public interest in this matter” in announcing the request at a hastily scheduled justice department news conference.

The news follows an FBI raid on the former US president’s resort home of Mar-a-Lago earlier in the week. That search was part of an investigation into whether Trump took classified records from the White House.

The DoJ has been investigating the potential mishandling of classified information since the National Archives said it had received from Mar-a-Lago 15 boxes of White House records, including documents containing classified information, earlier this year.

In a brief press conference announcing the move Garland said he personally authorized the decision to seek a search warrant of Trump’s home and that the decision had not been “taken lightly”.

Since the search Republicans, led by Trump, have attacked the FBI and the DoJ and accused it of conducting a politically motivated investigation. The fury of the Republican response has prompted fears that FBI agents and officials could be placed in danger.

Earlier on Thursday, an armed man decked out in body armor tried to breach a security screening area at an FBI field office in Ohio. The man then fled and exchanged gunfire in a standoff with law enforcement, authorities said.