A spate of arsons at black churches in several southern states has prompted a federal investigation, since they've occurred in rapid succession in the wake of the white supremacist massacre at a black church in South Carolina.

Six black churches have been burnt in the week and a half since Dlyann Roof entered the Emanuel AME Church in Charleston, SC and murdered nine congregants.

— Matt Murphy (@MattMurph24) June 28, 2015

Three of the incidents are being investigated as arson or as suspicious at this point — the fires in Warrenville, SC, Charlotte, NC, and Knoxville, Tenn. While a fire in Macon, Ga. is being treated as "suspicious." Meanwhile fires in Tallahassee, Fla. fire and Gibson County, Tenn., are under investigation but may have been started by faulty wiring and lightning, respectively.

The US Federal Bureau of Investigation confirmed Sunday that they were coordinating with local authorities to investigate the fires but that, for the moment, they do not believe them to be connected.

"They’re being investigated to determine who is responsible and what motives are behind them," FBI spokesperson Paul Bresson told Buzzfeed News. "I’m not sure there is any reason to link them together at this point."

— Chris Harvey (@Ctrill95) June 29, 2015

In the wake of the shooting in South Carolina, Dylann Roof's manifesto was found accompanied by photos, in some of which he can be seen posing with the rebel flag. The ensuing push to remove the flag — widely understood as a symbol of white supremacist racism — led many to expect a backlash against the black community, of which churches have historically been a cornerstone.

— Master Race Baiter (@FeministaJones) June 27, 2015

— Justice Hudson (@justicexhudson) June 29, 2015

— Improbable Joe (@ImprobableJoe) June 28, 2015

"You could actually feel the heat from the church," Adonica Simpkins told NPR about discovering that Glover Grove Baptist Church in Warrenville, SC was on fire. "The actual power lines, just started, pop, pop, pop! Then the power went off. It was terrible. You could see straight through the church, how it was burning."

— Joy Reid (@JoyAnnReid) June 28, 2015

Bobby Jones, the Pastor of Glover Grove, said it could be arson and it could be a hate crime.

"I hope not," he added."I hope from the bottom of my heart that it's not. I'm 72 years old, and I've never had a problem out of anybody."

"If it's a hate crime, it had to be somebody that's not from here," Jones said.

As President Barack Obama mentioned in his eulogy for Rev. Clementa Pinckney — one of the victims in the Charleston shooting — black churches have a long legacy of playing a key role in the civil rights movement.

"Over the course of centuries, black churches served as 'hush harbors' where slaves could worship in safety;" Obama said, "praise houses where their free descendants could gather and shout hallelujah, rest stops for the weary along the Underground Railroad; bunkers for the foot soldiers of the Civil Rights Movement."

As such, black churches also have a history of being targeted. Perhaps the most famous target was the 16th Street Baptist Church in Birmingham, Ala. which was firebombed in on Sept. 15, 1963, killing four young black girls.

"From slavery and the days of Jim Crow through the civil rights movement and beyond, white supremacists have targeted the Black church because of its importance as a pillar of the Black community, the center for leadership and institution building, education, social and political development and organizing to fight oppression," wrote David A. Love in the Atlantic.

"Strike at the Black church, and you strike at the heart of Black American life."