About 475 ballots were recovered Monday after an incendiary device was placed in a southwest Washington state ballot box.

Clark County Auditor Greg Kimsey said Tuesday election workers will go through what is left of the ballots on Wednesday to find the voters’ contact information, per The Hill.

He said workers will likely be able to pull voter information from some of the damaged ballots in order to get a new ballot for those voters, the Associated Press reported.

This incident is one of several that have recently plagued the northwest region of the U.S., The Hill reported.

Incendiary devices either damaged or destroyed ballots at a drop box in Vancouver, Washington, and damaged three ballots at a box in Portland, Oregon.

Federal, state and local officials have have called these instances an attack on democracy before a contentious Election Day.

Authorities have linked the two fires on Monday, as well as an Oct. 8 incident.

In the Oct. 8 incident, an incendiary device was placed at anther ballot drop box in Vancouver. However, no ballots were damaged.

U.S. Attorney Tessa M. Gorman and FBI Seattle Field Office acting special agent Greg Austin issued a joint statement on Tuesday, saying they are “working closely and expeditiously together to investigate the two incendiary fires at the ballot boxes in Vancouver, Washington, and the one in Portland, Oregon, and will work to hold whoever is responsible fully accountable.”

Portland and Vancouver are about 15 miles apart. 

Rep. Marie Gluesenkamp Perez (D-Wash.), who is running for reelection against Republican challenger Joe Kent for Washington’s 3rd Congressional District, said the burning of the ballot box is “unpatriotic.”