FBI investigating powdery packages mailed to state election officials

Sept. 17 (UPI) -- Threatening letters containing packages of non-toxic powders arrived at seven state offices Monday and triggered federal investigations.

No hazardous materials were found in the letters that contained packages of powder , but the FBI is warning state election officials and others to be wary of suspicious letters and packages that might arrive at their offices.

The FBI is "working with our partners to determine how many letters were sent, the individual or individuals responsible for the letters and the motive behind the letter," FBI officials said in a prepared statement.

A joint memo issued Monday by the FBI and the U.S. Postal Inspection Service says the two agencies are "working diligently to intercept any additional letters before they are delivered."

"The election community should remain vigilant and exercise caution when handling the mail," the joint memo says. "All suspicious substances should be treated as potentially hazardous and must be handled in accordance with established safety protocols."

The suspicious letters arrived at secretaries of state, state election offices and attorneys general offices on Monday in Iowa, Kansas, Maryland, Nebraska, Oklahoma, Tennessee and Wyoming.

The return addresses on each letter lists the sender as the U.S. Traitor Elimination Army by using the "U.S.T.E.A." acronym, the FBI said.

Kansas officials in Topeka received two of the suspicious packages mailed to a government building, which prompted the building's evacuation at 2:17 p.m. CDT on Monday.

One package was mailed to the Kansas Secretary of State office and the other to the attorney general's office, which are located in the same building.

Several office staff in both units were exposed to the powdery substances and underwent medical monitoring until law enforcement determined the substances weren't harmful.

State government buildings in Des Moines, Iowa, and Cheyenne, Wyo., also were evacuated until the substances were identified.

Law enforcement in Oklahoma determined a powdery substance received there was flour.