Authorities investigating 'suspicious' envelopes sent to election offices in 5 states

At least four envelopes tested positive for fentanyl, according to the FBI.

Federal authorities are investigating suspicious letters sent to election offices in five states – Washington, Oregon, California, Nevada and Georgia.

The FBI said that "in at least four instances, preliminary tests … indicated the presence of fentanyl," according to a bulletin disseminated to state and local law enforcement and obtained by ABC News.

An image of one of the letters obtained by ABC News indicates the intent was to "end elections now."

"We are in charge now and there is no more need for them," the letter reads.

Washington Secretary of State Steve Hobbs said in a statement Thursday that envelopes containing "unknown powdery substances" were discovered Wednesday by election workers in several counties, prompting evacuations of those offices.

An initial test of a white powdery substance in one envelope that was sent to the county elections office tested positive for fentanyl, the Spokane Police Department said.

Another letter sent to an election office in Washington state had a substance that tested positive for baking soda, not fentanyl, Officer Shelbie Boyd of the Tacoma Police Department told ABC News. The state will take it to a lab for additional testing.

Chris Loftis, the director of communications for Washington State Patrol, said a state bomb squad that responded to an election office in Pierce County on Wednesday found a message advising that the intent of the letter was to "stop the election."

In Georgia, Secretary of State Brad Raffensperger confirmed that election workers in Fulton County were sent a suspicious letter and that no other counties in the state appear to have been targeted.

The letter was intercepted before it arrived at the election office, Raffensperger said at a press conference. No motive has been determined, he said.

"We're working with our state and federal partners to determine if any additional Georgia officials are being targeted," Raffensperger said in a statement earlier. "Domestic terrorists will not trample on our right to free and fair elections."

A Fulton County spokesperson said no additional information was immediately available.

In Lane County, Oregon, officials also temporarily closed an election office on Wednesday after a suspicious piece of mail arrived, a county spokeswoman told ABC News.

"Certainly it's somber today," county spokeswoman Devon Ashbridge told ABC News. "I can't imagine coming to work and realizing that someone at minimum wanted to terrorize you and potentially harm you. We're doing what we can to support our staff."

While the incident in Oregon did not impact any election deadlines, Ashbridge said the office closure did delay ballot counting.

Officials in California also confirmed Thursday to ABC News that the Postal Service "intercepted two suspicious envelopes headed to local election facilities," but have not yet determined the contents of that mail.

Additionally, the Texas Department of Public Safety and the FBI are investigating a letter containing an unknown substance that was sent to the Attorney General of Texas' office, according to law enforcement. Initial tests on the substance came back negative, officials said Thursday.

Authorities did not say if the letter sent to the Texas AG is connected to the ones from other states.

Threats to election workers have become more frequent in recent years, prompting a troubling exodus from their ranks in the aftermath of the 2020 presidential election.

A DOJ spokesperson said in a statement Thursday, "We are aware of the reports and the FBI and U.S. Postal Inspection Service are investigating this matter. We have no further comment at this time."

FBI offices in Atlanta and Spokane confirmed that they were collaborating with local law enforcement to investigate the incidents.

"FBI Seattle, along with our law enforcement partners, responded to multiple incidents involving suspicious letters sent to ballot counting centers in Washington state," the office said. "As this is an ongoing matter, we do not have any further comment but the public can be assured that law enforcement will continue to keep the public's safety as its top priority."

The agency's main office said it is also investigating the incidents but didn't comment further citing the ongoing investigation.

"The public can be assured that law enforcement will continue to keep the public's safety as its top priority," the FBI said in a statement. "The FBI would also like to remind everyone to exercise care in handling mail, especially from unrecognized senders. If you see something suspicious, please contact law enforcement immediately."

ABC News' Jack V. Date, Luke Barr, Olivia Rubin, Laura Romero, Quinn A. Owen, John Santucci and Elizabeth Landers contributed to this report.