By CHRISTINA A. CASSIDY and ALI SWENSON, Associated Press

ATLANTA (AP) — Two ballot boxes in the Pacific Northwest were damaged in a suspected arson attack just over a week before Election Day. destroying hundreds of ballots at a location in Vancouver, Washington.

In the other, in neighboring Portland, Oregon, a fire suppression system appears to have worked to contain the fire and limited the number of damaged ballots to three. Authorities are reviewing surveillance footage as they try to identify who is responsible.

Here’s what happened, how rules and security measures around drop boxes vary across the country, and how election conspiracy theories have undermined confidence in their use.

What do we know?

Police said incendiary devices started the fires at drop boxes in Portland and Vancouver. Authorities said evidence showed the fires were connected and are also related to an Oct. 8 incident when an incendiary device was placed in a different mailbox in Vancouver.

Multnomah County Elections Director Tim Scott said his office planned to contact the three voters whose ballots were damaged in Portland to help them get replacements.

In Vancouver, hundreds of ballots were lost in a ballot box at the Fisher’s Landing Transit Center when the mailbox’s fire suppression system did not work as intended. Clark County Auditor Greg Kimsey said the box was last emptied at 11 a.m. Saturday. Voters who cast their ballots there afterward are urged to contact the office to obtain a new one.

The office will increase the frequency with which it collects ballots and shift collection times to evenings to prevent ballot boxes from remaining full overnight, when vandalism is more likely to occur.

Kimsey described the alleged arson as “a direct attack on democracy.”

When and where can mailboxes be used?

Drop boxes have been used for years in states such as Colorado, Oregon, Utah and Washington, where ballots are mailed to all registered voters.

Its popularity grew in 2020 during the COVID-19 pandemic, as election officials sought options for voters who wanted to avoid crowded polling places or were concerned about mail delays.

In total, 27 states and the District of Columbia allow ballot drop boxes, according to data compiled by the National Conference of State Legislatures. Another six do not have a specific law but allow local communities to use them.

Location can vary widely. In some communities, they are located inside public buildings and are available only during business hours. In other places, they are outside and accessible at any time, usually with video surveillance or someone watching.

Sporadic problems have occurred over the years.

In 2020, some mailboxes were struck by vehicles and one in Massachusetts was damaged by arson. In that case, most of the ballots were legible enough to identify voters and send them replacements. A mailbox was also set on fire in Los Angeles County in 2020.

How should they ensure themselves?

The U.S. Cybersecurity and Infrastructure Security Agency advises state and local election officials to place drop boxes in convenient, high-traffic areas that are familiar to voters, such as libraries and community centers.

If drop boxes are not staffed, they should be secured and locked at all times, located in well-lit areas and monitored by video surveillance cameras, according to the guidance. Many are bolted to the ground, monitored by cameras or confined to public buildings during business hours, where they can be monitored.

How have conspiracy theories contributed to concerns around mailboxes?

The ballot boxes have been in the spotlight for the past four years, targeted by right-wing conspiracy theories who falsely claimed they were responsible for massive voter fraud in 2020.

A discredited movie called “2,000 Mules” amplified the claims, exposing millions of people to an unfounded theory that a vote-harvesting operation was dropping fraudulent votes into mailboxes in the dead of night.

A Associated Press poll of state election officials across the US found that there were no widespread problems associated with drop boxes in 2020.

The paranoia about mailboxes continued until the 2022 midterm elections, when armed vigilantes began showing up to monitor them in Arizona and were restricted by a federal judge. This year, the conservative group True the Vote launched a website hosting live streams of citizens from mailboxes in several states.

In Montana, where a key U.S. Senate race is at stake, Republicans recently seized on a baseless allegation of ballot box tampering to raise money from questions about the electoral process.

How have states responded since the 2020 election?

Republican lawmakers in several states sought to tighten rules on mail-in voting after the 2020 election, with much of their attention focused on the use of drop boxes.

Since then, six states have banned them: Arkansas, Mississippi, Missouri, North Carolina, South Carolina and South Dakota, according to research by the Voting Rights Lab, which advocates for greater voting access.

Other states have restricted its use. This includes Ohio and Iowa, which now allow only one dropbox per county, according to the Brennan Center for Justice.