The gunman accused of killing nine black churchgoers in Charleston, South Carolina, last year was attacked in jail on Thursday while on his way to the shower, authorities said.

Dylann Roof, 22, reportedly suffered several bruises but was not seriously injured in the incident at the North Charleston jail. Another inmate, Dwayne Marion Stafford, 25, ran toward Roof and punched him several times near the showers, according to officials.

Charleston County Sheriff Al Cannon Jr. said in a press conference that Roof and his attorney had decided not to press charges against Stafford.

Cannon added that there was no proof that the reported attack by Stafford, who is black, was racially motivated , beyond the obvious speculation that we would all have given the nature of the situation, USA Today reported.