This security camera footage handout grab released by the Charleston (South Carolina) Police Department on June 18, 2015 shows the man suspected of killing nine people in a shooting at a historic black church (AFP Photo)

Washington (AFP) – A white gunman was on the run Thursday after fatally shooting at least nine worshippers in a historic black church in a southern US city in what police called a hate crime.

Churchgoers had gathered for a prayer meeting in the Emanuel African Methodist Episcopal Church on Wednesday evening in Charleston, South Carolina when the shooter walked in, sat in the congregation for about an hour, then opened fire, Charleston Police Chief Gregory Mullen said.

America’s latest mass shooting comes at a time of heightened racial tensions in the country, after several high-profile killings of unarmed black men at the hands of white police in recent months led to riots and a national debate on race.

In Wednesday’s attack, three men and six women were killed and several other people were wounded.

“At this point, we have nine victims in this hideous crime that has been committed,” Mullen told journalists.

“I do believe it was a hate crime.”

Among the dead was the church’s pastor Clementa Pinckney, who was also a South Carolina state senator, fellow politician Marlon Kimpson told US media.

Police said the suspect was a clean-shaven white man in his early 20s. As of 7:00 am Thursday (1100 GMT), he remained at large and officers swarmed the city with the help of helicopters and tracking dogs to try to find him.

Police released security camera images of the suspected gunman — a slender young white man with dark blond or brown hair in a distinctive bowl-type haircut, and wearing a grey sweater.

“He obviously is extremely dangerous,” Mullen said.