(NewsNation) — A memo issued by a federal law enforcement agency last week warned of increasing threats to federal officers following the search of former President Donald Trump’s Mar-a-Lago estate.

“Users in far-right, anti-government and conspiracy theory message boards have advocated for violence against FBI agents and other federal employees. Some have claimed that a civil war was imminent…” ” the bulletin said in part, which NewsNation obtained.

Another memo allegedly obtained by CBS says there was “a threat to place a so-called dirty bomb in front of FBI Headquarters” and threats of an “‘armed rebellion.'” U.S. agencies have identified “multiple articulated threats and calls for the targeted killing of judicial, law enforcement, and government officials associated with the Palm Beach search, including the federal judge who approved the Palm Beach search warrant.”

This comes after a gunman tried to break into the FBI Cincinnati field office last week.

FBI Director Christopher Wray did not tie the warning or Cincinnati incident directly to the FBI search of Donald Trump’s Mar-a-Lago estate on Monday, but rather said it was due to “recent media coverage” of the FBI.

Former FBI and CIA agent Tracy Walder said more online monitoring of social media sites like Gab, 4Chan and others needs to be done to protect federal agents from this kind of incident.

“The only thing you can tell (federal agents) is to be vigilant, to be aware to over-report any threats that you see,” Walder said. “Don’t second-guess yourself. If you see something, say something. It’s better to be overly cautious than not report anything at all..

Editor’s Note: NewsNation has clarified which memo it has obtained.

The Associated Press and Reuters contributed to this report.