Racist murderer Dylann Roof
Racist murderer Dylann RoofReuters

Dylann Roof - the 21-year-old white supremacist arrested over a massacre at a Black church in Charleston, South Carolina - has confessed to police to the murder of the nine people gunned down in cold bloody Wednesday night.

According to CNN, Roof told police that he had opened fire with his .45-caliber pistol in order to start a "race war."

Law enforcement officials had already been treating the murders as a hate crime. Witnesses revealed Roof took part in the weekly Bible study class at the church before suddenly standing up and saying he was there "to shoot black people," before lethally opening fire.

Witnesses also say that when one of the victims begged him to stop he responded: "No, you've raped our women, and you are taking over the country ... I have to do what I have to do."

He also told an elderly woman that he would allow her to survive so that she could tell people what he had done "because I'm going to kill myself."

Also on Friday, South Carolina's Governor Nikki Haley has said the state will be seeking the death penalty for Roof if he is convicted of the slaughter.

"We will absolutely want him to have the death penalty," Haley told NBC.

Roof is due to make his first court appearance later today.

He was arrested on Thursday some than 245 miles away in Shelby, North Carolina, after a local resident reported a suspicious vehicle to police.

Roof was then arrested by police without incident, though he was still armed at the time.

Later that day, he appeared cuffed and surrounded by armed police officers after being flown back to Charleston to stand trial.