ATLANTA -- Confederate battle flags were stealthily placed on the grounds of the Rev. Martin Luther King Jr.'s church, and authorities said Thursday they were looking for two white males who were recorded on surveillance camera leaving the banners behind.
Atlanta police Chief George Turner said his agency was working with federal authorities and they have not determined what charges might be levied. Turner said they have not ruled out a hate crime.
An officer from the Atlanta FBI's joint terrorism task force was on the scene "to better determine if any specific threats were received" and to provide support to Atlanta police, FBI Special Agent Steve Emmett said in an email.
Police said two men were caught on surveillance video arranging the flags around the property, CBS affiliate WGCL in Atlanta reported.
King preached at Ebenezer Baptist Church on Auburn Avenue, once a bustling center of commerce for Atlanta's African-American businesses and residents. The Martin Luther King Jr. Center for Nonviolent Social Change, the historic church and its new building - where congregants now meet and where the flags were placed - are a short walk from the home of King's grandparents, where the slain civil rights leader lived for the first 12 years of his life.
The Rev. Raphael Warnock, senior pastor at Ebenezer, called placing the flags a "terroristic threat."
"It is a hateful act," he said. "I view it as an effort to intimidate us in some way, and we will not be intimidated."
It was the latest volley in the fight over the Confederate flag and Civil War-era monuments ever since a white gunman was accused of killing nine black church members in South Carolina. Statues of the Confederacy have been vandalized around the South, and state governments in South Carolina and Alabama have removed battle flags entirely from Capitol grounds.
Atlanta police Officer Gary Wade said a maintenance worker discovered the flags at 6 a.m. Thursday and notified the National Park Service, which operates the Martin Luther King Jr. National Historic Site, which is adjacent to the church.
"Our grounds men were so upset, they took pictures and then they moved them," said the Rev. Shanan Jones of Ebenezer Baptist.
The flags weren't stuck in the ground but instead set neatly on top of it. One was placed on the ground near a bell tower and poster that said: "Black Lives Matter." The slogan has become part of a movement of civil rights supporters who say police treat blacks unfairly.
A conference on the role on black churches in social justice issues has been going on in Ebenezer's facilities. Warnock said the hateful act only strengthens their resolve, and he promised the city would remain peaceful.
Confederate flags have been placed at the King Center before.
"It was disturbing and sickening, but unfortunately not terribly surprising," Warnock said of the latest incident. "We've seen this kind of ugliness before."