Following the discovery of two improvised explosive devices (IEDs) amid the pro-Trump mob in Washington, D.C., yesterday, Virginia police instructed officers to be on the lookout for suspicious packages, according to an internal bulletin obtained by The Nation.

The information bulletin, dated January 6, was issued by the Arlington County Police Department’s Homeland Security Section. It states that “officers are advised to be aware of their surroundings at all times and to treat any suspicious device/package as legitimate,” though it stresses that there is no specific indication that any IEDs were deployed in Arlington County. The bulletin also describes the two IEDs found in D.C.

“On January 6th two devices were located near the 300 block of First St SE and the 400 block of Canal St., in Washington, DC. As of this writing MPD [Metropolitan Police Department] EOD [Explosive Ordnance Disposal] units are in the process of disrupting the devices which appear to be Improvised Explosive Devices (IED’s)).”

The pro-Trump mob that descended on the Capitol yesterday was considered such a serious threat that both the FBI’s headquarters and its Washington Field Office sent many staff home, according to one current and one former FBI official familiar with the matter. (Personnel specializing in counterterrorism and criminal matters are said to have remained.)

It remains unclear how the crowd of Trump supporters managed to gain entry to the Capitol.

“The only reason you get to breach the Capitol is you let it happen,” an FBI official told The Nation. “Why did Capitol Police not have a plan?”

“There was no intelligence that suggested that there would be a breach of the U.S. Capitol,” D.C.’s Metropolitan Police chief reportedly said. But the event had been promoted on social media for at least days prior. Furthermore, unrest relating to the election had been anticipated by multiple federal agencies. In September, the FBI identified the period between the presidential election and Inauguration Day “as a potential flashpoint,” according to an FBI intelligence assessment previously obtained by The Nation.

Another intelligence assessment, conducted by the Department of Homeland Security (DHS) and obtained by The Nation identified “white supremacist extremists” as the foremost threat to the election. An army intelligence report leaked to me also made reference to DHS intelligence in relation to the election, stating, “DHS assessed white supremacist extremists to be the most persistent and lethal threat.”

Another reason for the security failure was the delayed deployment of the DC National Guard, which President Trump reportedly resisted. Another cause of the delay not previously reported is that the DC National Guard lacked riot gear, because much of it was in the possession of active-duty military personnel. It had been lent to them this summer as part of Trump’s controversial plans to deploy active-duty military to subdue protests, according to a current law enforcement official familiar with the matter.