Since an avowed white supremacist massacred nine members of the Emanuel African Methodist Episcopal Church in Charleston, South Carolina during Bible study two weeks ago, fires have been reported at seven predominantly black churches across the South, heightening faith communities' fears of racially motivated violence.

Of those seven fires, three have been ruled arson. Two others were electrical, one was sparked by lightning, and the cause of the other has been ruled undetermined.

The first blaze reported at a Southern black church following the June 17 Charleston shootings occurred at the College Hill Seventh Day Adventist Church in Knoxville, Tennessee on June 21. Someone set fire to bags of dirt and bales of hay outside a church door and burned a church van. The incident has been ruled arson.

Early on June 23, fire was reported at God's Power Church of Christ in Macon, Georgia. When firefighters arrived, they found the front door wired shut. That incident has also been ruled arson.

The following day, a massive fire was reported at Briar Creek Baptist Church in Charlotte, North Carolina; investigators found it had been intentionally set. Total damage to the church has been estimated at $250,000.

On June 26, fires were reported at two more black churches. The blaze at Greater Miracle Apostolic Holiness Church in Tallahassee, Florida has been determined to have been electrical, sparked when a tree fell on wiring. The cause of the other fire, which destroyed the Glover Grove Baptist Church in Warrenville, South Carolina, was classified as "undetermined."

On Monday of this week, fire broke out at Disciples of Christ Ministries in Jackson, Mississippi. Investigators believe that fire was also electrical. Then on Tuesday night, a fire was reported at the Mt. Zion AME Church in Greeleyville, South Carolina. Investigators say they think it was caused by lightning.

The church fires have raised fears that black institutions are being targeted, perhaps as part of a backlash against efforts to remove the Confederate flag from public buildings following the Charleston massacre. The shooter in that case, 21-year-old Dylann Roof, took pictures posing with Confederate flags.

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

The incident at Mt. Zion AME brought up chilling memories because that church was burned to the ground by the Ku Klux Klan in 1995 during a nationwide outbreak of arsons and bombings of black churches. The National Church Arson Task Force created by President Bill Clinton investigated a total of 827 cases of arsons, bombings and attempted bombings of houses of worship between 1995 and 1999. Those included 269 incidents involving predominantly African-American churches, with 185 of them located in the South. Of the 84 arrests for arsons and two arrests for bombings of black churches during that period, three-quarters involved white perpetrators, almost all of them men.

That outbreak of attacks recalled the violence directed at black churches during the civil rights movement of the 1960s by white supremacists. In one six-month period during 1964, almost 40 churches burned in Mississippi alone.

The FBI is investigating the recent outbreak of church fires in coordination with the Department of Justice and the Bureau of Alcohol, Tobacco, Firearms and Explosives, which investigates arsons and bombing. So far law enforcement officials have not determined that any of the blazes were directly related or were definitively hate crimes.

"We are looking into these matters," said Eric Treene of the DOJ's Civil Rights Division, "but we want to caution folks not to jump to conclusions."

Treene made his remarks during a webinar convened on Wednesday by the Federal Emergency Management Agency titled "Resources to Help Prepare Houses of Worship for Emergencies." The online gathering, which drew over 1,000 people and also featured speakers from the Department of Homeland Security and the FBI, was an effort to calm church leaders' fears in the aftermath of Charleston and the recent fires, and to ensure religious institutions have done all they can to protect themselves from violence. Speakers emphasized how important it is for houses of worship to draw up emergency plans and work proactively with local first responders to ensure they're familiar with the plans.

Treene noted that there are about 1,700 fires at faith institutions across the U.S. each year. According to the National Fire Protection Association, about 16 percent of those fires are set intentionally. But as the Washington Post reported, "fire" can mean anything from an accidental brush fire outside to a small kitchen fire. Almost half of all religious property fires are classified as "confined," meaning they're restricted to a small area and don't cause major property damage.

Vashti McKenzie, a bishop in the AME Church, was among those who spoke as part of the webinar. She acknowledged the uncertainty communities are experiencing as violence invades places that are supposed to be sanctuaries. But she cautioned faith institutions against allowing fear to get in the way of their mission.

"When we talk about safety we want to be practical, we want to be vigilant," McKenzie said. "But let's not close our doors. Let's keep our doors open so we can continue to provide the services we provide."

(For a recording of the webinar and a list of resources shared there, click here.)