Nine people were killed when a white gunman entered a historic African-American church in the US city of Charleston, South Carolina, and opened fire, the city's police chief said on Thursday.

One other person was wounded and taken to a hospital, Chief Gregory Mullen told reporters about four hours after the shooting on Wednesday evening.

Describing the shooting as a hate crime, Mullen said: "It is unfathomable that somebody in today's society would walk into a church when people are having a prayer meeting and take their lives."

He also said that an all-clear had been sounded after an earlier bomb threat in the area of the church. – Reuters