White powder threats sent to Boehner, other members of Congress

Several members of Congress received threatening letters this week at their home offices containing a suspicious powder.

The Federal Bureau of Investigation and the Senate's top law enforcement officer announced that, in all cases, the powder proved to be harmless, according to the Wall Street Journal.

Sergeant-at-Arms Terrance Gainer said that the letters were mailed to three state and home district congressional offices. A district office of House Speaker John Boehner (R-Ohio) was among those targeted by the threats.

"The author of these letters has indicated that additional letters containing a powdery substance will be arriving at more Senate offices and that some of these letters may contain an actual harmful material," Gainer said in a memo to Senate offices, the Wall Street Journal reports. "Although all letters received thus far have proved harmless, it is essential that we treat every piece of suspicious mail as if it may, in fact, be harmful."

The letters all bore a return address from "the MIB," were mailed from Portland, Oregon, and told recipients that there was a 10 percent chance that they had just been exposed to "a lethal pathogen," according to the Wall Street Journal.

"So far, none of the letters have contained a hazardous substance," FBI Special Agent Jason Pack said, the Wall Street Journal reports. "We are working with those law enforcement agencies affected to determine if the mailings are related. We take these matters seriously and will investigate fully."