Federal authorities are investigating fires at two ballot boxes in the Portland, Oregon, area, believed to have been caused by incendiary devices.

In Portland, security personnel quickly extinguished the fire, which damaged three ballots, and officials will contact affected voters to reissue ballots.

In Vancouver, Washington, a second ballot box fire damaged hundreds of ballots, and voters who deposited ballots after 11 a.m.

Saturday are encouraged to verify their status, CNN has reported.

Authorities condemned the incidents as attempts to disrupt the electoral process, with increased concern over ballot box security as election tensions rise.

Written by B.C. Begley