The latest in a series of dangerous sounding deliveries to the Beltway arrived in Arlington, Virginia, where a military facility was evacuated late Thursday morning after personnel discovered an envelope containing white powder, according to a statement released by the U.S. Navy:

A suspicious substance was found in the mailroom of Building #12 at Naval Support Facility - Arlington, Va. As a precaution, all personnel are currently being evacuated. The situation is ongoing and currently under investigation and we will provide additional details as they become available.

An unnamed military official told Foreign Policy that approximately 800 staff members were shuttled out of the facility, situated about two miles from Washington, D.C., just west of the Potomac River:


 

The incident comes the day after Mississippi police arrested and jailed a 45 year-old man named Paul Kevin Curtis for allegedly mailing a ricin-laced envelope to Mississippi Senator Roger Wicker. (Senate Sergeant-at-Arms Terrance Gainer repeatedly confirmed on Thursday that multiples tests showed the envelope addressed to Wicker did in fact contain ricin, a poison known for triggering false positives, telling reporters that "Our field tests indicate it was ricin. Our lab tests confirm it was ricin. So I don't get why others are continuing to use equivocal words about this.")

Meanwhile, authorities are currently testing another envelope suspected of containing ricin that was addressed and mailed to President Obama earlier this week.) It's unclear if the suspicious powder discovered in Arlington is linked to either envelope. But this sure seems familiar to the heightened state of tension on Capitol Hill after 9/11, or at least some on Capitol Hill are making the connection these "suspicious substance" deliveries and the antrax mailings of 2011. Here's House Homeland Security Committee Chair Michael McCaul on CNN last night: