President Barack Obama has publicly mourned the deaths of nine people in a Charleston, South Carolina church, saying the shooting late Wednesday night carried out by a white gunman revives memories of a "dark part of our history."

Speaking from the White House on Thursday morning, Obama revealed that he and First Lady Michelle Obama personally knew members of the Emanuel AME Church, including pastor Rev. Clementa Pinckney, who was among those killed.

"To say our thoughts and prayers are with them...doesn't say enough..to describe the anger and sadness we feel," he said. "Any death of this sort is a tragedy, any shooting involving multiple victims is a tragedy, [but] there is something particularly heartbreaking about death happening in a place which we seek solace, we seek peace, a place of worship."

He added, "I've had to make statements like this too many times. Communities like this have had to enture tragedies like this too many times...we know that once again, innocent people were killed in part because someone wanted to inflict harm had no trouble getting their hands on a gun...At some point we as a country will have to reckon with the fact that this type of mass violence does not happen in other developed countries."

The attack, which was carried out by a white gunman identified as Dylann Roof, 21, has been called a "hate crime" and the city's mayor has labeled it as an act of "pure hatred."

According to reports, Roof began firing at the Emanuel African Methodist Episcopal Church on Calhoun Street, a historic structure with roots dating back to 1816, around 9 p.m. Wednesday night, after attending the Bible session for over an hour. Eight people were killed on the scene, while two others were transported to a nearby hospital, one of whom died along the way.

Although he fled the scene after killing nine people, Roof was caught 14 hours later about 200 miles away, in Shelby, N.C., a town west of Charlotte on Thursday morning and taken into custody, NBC News reports.

State Senator Lawrence K. Grooms said Mr. Pinckney, who was a Democratic member of the state senate in addition to the church's pastor, had had "a voice you could pick out of a crowd, a booming voice."

"He was my friend, he was my colleague, but he was also my brother in Christ," said Senator Grooms, who drove down from the Statehouse as soon as he heard the news last night.

Pinckney, 42, leaves behind his wife and two children.

Two other men and six female church members were also killed, and one 5-year-old girl reportedly survived the attack by fooling the gunman by pretending to be dead, according to reports.

Pinckney's cousin, Sylvia Johnson, who spoke with survivors of the attack, revealed that the gunman sat next to Pinckney for the entire prayer meeting. He also reportedly reloaded his gun five times during the attack, while her son tried to talk him out of killing more people.

One survivor revealed that Roof carried out the deadly attack because he allegedly believed blacks are "taking over" America and "have to go."

"You rape our women and you're taking over our country," Johnson said, NBC News reported. The survivor recalled the gunman shouting. "And, you have to go."

Speaking at a press conference Thursday morning, Charleston Mayor Joseph P. Riley said there is no other way to explain the brutal crime but as an "unfathomable" tragedy.

"The only reason that someone could walk into a church and shoot people praying is out of hate," Riley said. "It is the most dastardly act that one could possibly imagine, and we will bring that person to justice. ... This is one hateful person."

"This is an unfathomable act, an unspeakable act by somebody filled with hate and with a deranged mind ... this person is dangerous," Riley added. "In Charleston, to have a horrible, hateful person go into a church and kill people there to pray and worship with each other is something that is beyond comprehensible and is not explained."

Meanwhile, Rev. Franklin Graham has urged Christians around the U.S. to pray for members of Emanuel A.M.E. Church, the families of the victims, and the Charleston, N.C. community as they mourn the loss of their loved ones and attempt to heal from the horrific tragedy.

On Thursday, Graham, who is the president of Samaritan's Purse and the Billy Graham Evangelistic Association, took to Facebook to offer his sympathies:

"Our hearts go out to all the members of Charleston's Emanuel A.M.E. Church, the families of the victims, and the Charleston community in the wake of last night's ‪#‎Charlestonshooting‬ at their Wednesday night prayer meeting. Nine lives tragically lost, including their pastor and South Carolina State Senator, Reverend Clementa Pinckney. Join me in praying for them and that the person responsible will be brought to justice quickly."