Confederate flags left at Atlanta church and MLK visitor center

When the sun came up on Atlanta's Ebenezer Baptist Church Thursday morning, four Confederate flags lay strewn across its grounds. A maintenance man discovered the flags at around 6 a.m., The Atlanta Journal-Constitution (AJC) reports, finding one beneath a poster that read "BLACK LIVES MATTER, HANDS UP."

The church is part of a complex of several historic buildings, which together make up the Martin Luther King, Jr. National Historic Site.

Police told AJC that the church had security cameras, but it was not immediately clear whether they captured anything pertinent. The Church's Rev. Raphael Warnock told the paper that Homeland Security had been called to investigate. Warnock had been scheduled to meet with other clergy on Thursday, to discuss the mass incarceration of African-American men.

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The incident comes amid heightened fears of white supremacist attacks on historic black churches, after the murder of nine African-Americans at the Emmanuel AME Church in Charleston on June 17. It also marks the second time this week that AJC has reported on the Confederate flag being used as an apparent intimidation tactic against African-Americans in Georgia. On Monday, a video of a heated confrontation between a convoy of Confederate flag-bearing pick-up trucks and a black child's birthday party went viral. While initially perceived as a deliberate attempt to intimidate the partygoers, later reports suggested that the trucks may have happened upon the party accidentally.

But for Warnock, there was nothing accidental about the careful placement of four Confederate flags at a historic site dedicated to Martin Luther King.

“Let the message go out that we will not be shaken by this,” the reverend told AJC. "This is a terrorist act."