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

Clark County Auditor Greg Kimsey said Tuesday that election officials will review what remains of the ballots Wednesday to find voters’ contact information. by The Hill.

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

The incident is one of several that have recently hit the northwest region of the United States, The Hill reported.

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

Federal, state and local officials have called the cases an attack on democracy ahead of a contentious Election Day.

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

In the October 8 incident, an incendiary device was placed in another ballot box in Vancouver. However, no ballot papers were damaged.

United States Attorney Tessa M. Gorman and FBI Seattle Field Office Acting Special Agent Greg Austin released a joint statement statement Tuesday, saying they are “working together closely and quickly to investigate the two arson fires at the polls in Vancouver, Washington, and Portland, Oregon, and will work to hold those responsible fully accountable.”

Portland and Vancouver are approximately 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 ballot burning was “unpatriotic.”