Threatening mailings containing suspicious powder hit Capitol Hill

Threatening messages containing suspicious powder and previously only sent to lawmakers’ district offices have now been directed to congressional offices on Capitol Hill.

On Monday, Senate Sergeant at Arms Terry Gainer circulated an email to Senate offices, warning them to remain alert regarding the mailings.

“In addition to the suspicious letters sent to Senate state offices last week, similar letters addressed to Senate offices in D.C. have been received,” wrote Gainer.

Last week, district offices for lawmakers including Sens. Joe Lieberman (I-Conn.), Patty MurrayPatty MurrayElection-year politics: Senate Dems shun GOP vulnerables Congress approves .1B in Zika funds Lawmakers pledge push for cures bill in lame-duck MORE (D-Wash.) and Pat RobertsPat RobertsGOP senators ask watchdog to examine Gitmo site surveys spending Senate panel approves pension rescue for coal miners Congress set for Saudi showdown with Obama MORE (R-Kan.) received such letters, according to local news reports.

The offices on Capitol Hill to have received mail threats have yet to be revealed.

“We are not disclosing the identities of the offices that have received the mail,” a Senate Sergeant at Arms employee told The Hill Monday.

The Capitol Police did not immediately respond to a request for comment on the matter Monday.

According to Gainer, the letters were all intercepted at the Senate’s off-site mail screening facility Monday morning. Tests of the letters thus far indicate they contain no hazardous materials.

Gainer also assured congressional staff that the FBI and Capitol Police continue to investigate the matter, and that there would be no interruption of congressional mail delivery.

“Arrival of the letters in D.C. today is further evidence of the bothersome commitment of the individual or group behind these mailings,” Gainer concluded. “All staff, here in D.C. and in the state offices, should remain vigilant and follow our established mail-handling protocols.”

Gainer also confirmed that all the threatening mailings received thus far have been postmarked from Portland, Ore. Last week, Gainer circulated an email to congressional staff warning them to be on the lookout for similar mailings, or those bearing the specific return address containing The MIB, L.L.C.

Members of Congress have not been the only reported targets of the mail attack. Letters addressed to comedians Jon Stewart and Stephen Colbert were also sent to parent company Viacom last week. The FBI is also reportedly investigating the matter.