The package was sent with a return address to the “U.S. Traitor Elimination Army” and a preliminary investigation showed the powder is likely harmless, officials said.

A suspicious package was sent to the Colorado secretary of state but was intercepted at a mail facility in Denver Tuesday. The package contained a white powder that investigators say was harmless, according to a press release from the secretary’s office.

Authorities are investigating a suspicious package addressed to the Colorado Secretary of State's Office.

A suspicious package has been sent to the California secretary of state, as well as election officials in at least 15 other states. No one has been hurt.

Griswold said in a statement, "We cannot tolerate threats to election officials and public servants. These threatening mailings are unacceptable, and we must condemn these actions in the strongest possible terms.

The FBI and the U.S. Postal Service are still investigating a string of suspicious envelopes that were delivered to or received by the secretary of state offices in at least 15 states, including Missouri.

A 'suspicious package' was sent to the California secretary of state headquarters in Sacramento, officials confirmed on Thursday. The announcement comes the same week the FBI said it was investigating the origin of suspicious packages sent to or received by election officials in more than 15 states.