Federal agents were seen Friday morning searching the Maryland residence of former Trump national security adviser John Bolton, ABC News has learned.

Sources familiar with the matter told ABC News that the search, carried out by the FBI, is related to allegations that Bolton is in possession of classified records. “NO ONE is above the law… @FBI agents on mission,” FBI director Kash Patel said on social media. It was not immediately clear what sensitive records federal investigators believe Bolton may have possessed. The federal agents, along with approximately six FBI vehicles, were seen at Bolton’s home for over an hour early this morning around 7 a.m. Local Montgomery County police were observed by ABC News blocking both entrances to Bolton’s street but have since left.

Agents were seen coming in and out of the house and it is still unclear if anything was removed from inside Bolton’s home.

The extraordinary move comes as President Donald Trump has recently ramped up pressure on the Justice Department to bring charges against his political opponents.

Bolton has long been a target of Trump’s ire. Most recently Trump has taken aim at Bolton’s criticisms of Trump’s engagements with Russian President Vladimir Putin.

A federal magistrate judge in Maryland signed off on the search, sources said.

To obtain a search warrant, investigators need to have probable cause of a violation of federal law.

That means authorities would need to convince a judge that there is sufficient reason based on known facts to believe that a crime has been committed, or that a certain property is connected with a crime.

The search, however, does not mean prosecutors have determined Bolton committed a crime.