WASHINGTON — Federal authorities are offering a $25,000 reward in connection with a series of arson incidents involving ballot boxes in Washington state and Oregon during early voting last month.

The FBI said Wednesday it is seeking the public's assistance in identifying a suspect sought in three incendiary fires.

The agency is offering a $25,000 reward for information leading to the identification, arrest and conviction of the suspect responsible.

The first incident occurred on Oct. 8 in Vancouver, Washington, when a ballot box was set on fire between 3:30 a.m. and 4 a.m. local time, the FBI said.

Then, on Oct. 28, ballot boxes in Vancouver and Portland were set on fire between 2 a.m. and 4 a.m. local time, the FBI said. Hundreds of ballots were damaged in the Vancouver incident after a fire suppression device failed to work properly, officials said.

In all three incidents, an "improvised incendiary device" was placed on the ballot drop boxes, the FBI said.

The Portland incident was captured by a surveillance camera, including a vehicle driven by the suspect believed to be responsible for these crimes, the FBI said.

In a roughly 3-minute video released by the FBI, a vehicle can be seen stopping next to the ballot box, located on a sidewalk. The driver appears to light an item and pass it through the driver's window, then drives away. Almost immediately after the vehicle departs, the ballot box begins smoking, then briefly sparking. Fire suppressants prevented further damage and protected nearly all the ballots, according to elections officials.

The vehicle was described by the FBI as an early 2003 to 2004 Volvo S-60 sedan, dark in color, with dark wheels and a light-colored interior. It does not have a Volvo logo on the front grill, the FBI said.

"At the time of the October 28, 2024, incidents, the vehicle also displayed a fraudulent temporary Washington license plate on the rear and no front license plate. The plate, which is not associated with a Volvo, may no longer be on the vehicle," the FBI said.

"It is believed that he may have some experience with metal work and welding," the FBI said.

The incendiary device used in the initial incident had "Free Gaza" and "Free Palestine" on it, two sources familiar with the ongoing investigation previously told ABC News. The two subsequent devices carried the slogan "Free Gaza," according to the sources.

One of the sources told ABC News it was unclear whether these markings reflect the views of a pro-Palestine activist -- or if it was an individual trying to manipulate existing divisions in the U.S.

ABC News' Pierre Thomas contributed to this report.

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