Secretary of State Adrian Fontes said the envelope arrived around 3:30 p.m. and was addressed to his office, rather than to a specific person. He described it as a targeted threat. No injuries were reported, and the investigation remains active, according to DPS spokesperson Bart Graves.

Staff contacted law enforcement and hazardous-materials responders, isolated the material and two people who had been exposed, evacuated other employees and restricted access to the floor. DPS laboratory testing determined the powder was not hazardous. Fontes said authorities had not told his office what the substance was.

Fontes said his office returned to normal operations the following day, while remaining vigilant. He said security had already been increased ahead of the midterm elections and that staff followed established procedures during the incident.

Threats against election workers undermine the ability of public servants to do their jobs, Fontes said, adding that mailroom staff should not have to work in fear. He urged voters to respond to intimidation by participating in elections.

The Executive Tower also houses the offices of Gov. Katie Hobbs and other state officials. Hobbs said she was grateful for the rapid response and called threats against public servants unacceptable, saying those responsible should be held accountable.

The Arizona incident comes as federal agencies investigate suspicious mailings sent to election offices and other addresses around the country. The FBI said it and the U.S. Postal Inspection Service are working with law enforcement partners to respond to reports of suspicious letters, some of which contained unknown substances, and to identify those responsible.

Authorities have not said whether the Arizona envelope contained a note. The FBI and DPS investigation is ongoing.