Two ballot drop boxes were set on fire early in Portland, Ore., and Vancouver, Wash., on Monday morning, destroying hundreds of ballots, according to officials.

At around 3:30 a.m. in east Portland, city police responded after an “incendiary device” was used to set a fire inside a ballot box. The fire was extinguished by local security that worked in the area before police arrived, according to a news release.

In Vancouver, about 10 miles away across the Columbia River, another ballot box was set on fire with a “suspicious device” at 4 a.m., local police said in a release. Hundreds of ballots in that drop box were destroyed after an internal fire suppression system failed, AP reported.