A Tennessee social justice center that has hosted iconic civil rights leaders was destroyed in a fire and a "white power" symbol was found on the site, the center said.

The symbol, which officials did not describe but said was connected to the white power movement, was discovered after the main office was completely destroyed in a fire last week, the Highlander Research and Education Center said in a news release Tuesday. It was spray-painted on the parking lot connected to the main office.

No one was hurt in Friday's blaze.

"While we don't know the names of the culprits, we know that the white power movement has been increasing and consolidating power across the South, across this nation, and globally," Highlander said. "Since 2016, the white power movement has become more visible, and we’ve seen that manifest in various ways, both subtle and overt."

The Highlander Center smolders after a fire on March 29, 2019. Courtesy New Market Vfd

Highlander, 30 minutes east of Knoxville, has provided training and organizing efforts for emerging social justice movements in the South since 1932, when Myles Horton founded the Highlander Folk School.

It played a key role in the civil rights movement by helping to organize the Montgomery, Alabama, boycotts and aided in the founding of the Student Nonviolent Coordinating Committee, according to the center's website.

Famed civil rights leaders and social activists including Martin Luther King Jr., Rosa Parks, Ralph Abernathy and Peter Seeger attended training events at the Highlander center.

Highlander on Tuesday called for the community to stay aware.

"Now is the time to be vigilant. To love each other and support each other and to keep each other safe in turbulent times," Highlander said. "Now is not the time to dismiss how scary things are, which makes it even more important to have concrete assessments of concrete conditions, and sophisticated strategies to build a new world."

Highlander's main office was home to decades' worth of documents, speeches and memorabilia that was lost in the fire, the center said on Facebook.

The Jefferson County Sheriff's Office on Saturday said in a statement that investigators were working with state bomb and arson agents to determine the cause of the fire.

"We are investigating a symbol that was painted in the parking area of the office to see if it has any affiliation to any individual or group," the sheriff's office said.

Highlander's office burned one day after the Oklahoma Democratic Party headquarters and a Chickasaw Nation office were vandalized with racist graffiti. The offices were spray-painted with messages that included a swastika, "1488" — which is frequently used by white supremacists and refers to Adolf Hitler — and anti-Chinese slurs.

Republican Gov. Kevin Stitt called the vandalism "abhorrent," and U.S. Reps. Tom Cole and Markwayne Mullin, both Republicans and Native Americans, condemned the images.

"There is no place in our communities for such despicable symbols and language so clearly meant to threaten other human beings and those with differing points of view," Cole said.