Police have arrested at least four people on suspicion of arson in the massive, still-growing wildfires across the western United States.

Several false reports earlier surfaced, pinning numerous fires on 'anti-fascist activists.'

However, after investigation, the FBI has learned that the reports were false.

Those rumors started from a tweet from the Portland, Oregon, police warning protesters holding rallies across the city.

The police had warned demonstrators that setting fires could lead to larger, more destructive blazes.

In the tweet, they said:

"To those attending the demonstration tonight: Keep in mind the immediate risk the use of fire poses to community members."

"Since fire danger is very high right now due to high winds and the current dry climate, fire will spread quickly and could affect many lives."

However, several state authorities now say at least four of the massive fires that have destroyed millions of acres in California, Oregon, and Washington, are suspicious.

Cops Have Arrested At Least Four Suspects in Connection to Incidents of Arson

In California, the police arrested suspect Anita Esquivel for setting fires along Highway 101. They then booked her into the Monterey County Jail on arson charges.

Police haven't learned the motive for Esquivel's alleged arson. However, they believe she's not a member of any Antifa-type organization.

Oregon cops also arrested Michael Jarrod, who lived in Oregon's woods, on three charges: Two counts of arson, 15 counts of criminal mischief, and 14 counts of reckless endangerment.

According to Oregon Live, Jarrod is responsible for setting one of two major wildfires in the state.

These two fires have now merged, killing at least 24 people, leaving hundreds homeless, and blazing more than 5,700 acres.

Oregon authorities have now warned area residents to prepare for a 'mass fatality incident' due to the fires.

In Washington, police also said they've nabbed two suspects who set small fires in an intersection of two state highways.

Meanwhile, fires in Oregon, Washington, and California continue to rage.

The fire has displaced more than half a million people in Oregon, per CNN. Tens of thousands are also evacuating in Washington and California.

The latest reports also suggest that at least 20 people have died in California and 24 in Oregon. And in Washington, a firefighter died while struggling to contain a fire.

According to the National Interagency Fire Center, more than 100 wildfires across 12 Western states have burned more than 4.3 million acres.