A man armed with a high-powered rifle and a handgun has killed three Black people at a store in Jacksonville, Florida, before shooting himself, in what local law enforcement describe as a racially motivated crime.

“This shooting was racially motivated, and he hated Black people,” Jacksonville Sheriff TK Waters told a press conference.

The suspect, whom Waters described as a white male wearing a tactical vest, was not identified. Waters said all three victims – two men and a woman – were Black.

Waters said authorities believed the shooter acted alone, and that before the shooting he had authored “several manifestos” for media, his parents and law enforcement detailing his hatred for Black people.

The sheriff described the weapons used as a Glock and an “AR-15 style” rifle decorated with swastikas.

“The hate that motivated the shooter’s killing spree adds an additional layer of heartbreak,” Waters said.

FBI takes charge

He said the shooter was spotted at a local historically Black college, Edward Waters University, where he put on his vest and a mask before going to the local branch of the Dollar General, a discount chain with stores across the United States.

Sherri Onks, special agent in charge of the Jacksonville FBI office, said federal officials had opened a civil rights investigation and would pursue the incident as a hate crime.

“Hate crimes are always and will always remain a top priority for the FBI because they are not only an attack on a victim, they’re also meant to threaten and intimidate an entire community,” Onks said.

Earlier, Jacksonville Mayor Donna Deegan told television station WJXT “there are a number of fatalities” inside the store but didn’t give a precise number.

“This is unacceptable,” Deegan told the station. “One shooting is too much but these mass shootings are really hard to take.”

Numerous police officers were in the area near Edward Waters University, a small historically Black university.

Students were being kept in their dorms, the school said in a statement, and no students or faculty were believed involved.

‘I don’t know if it’s safe to move’

Local resident Penny Jones told The Associated Press she worked at the store until a few months ago.

“I’m just waiting to hear about my co-workers that I used to work with,” Jones said. “I don’t know if it’s safe to move about the neighbourhood.”

Jones added that she was “feeling awkward, scared.”

“I don’t want to leave my house. I’m thinking, do I want to go back to the store? Is this going to start happening more frequently? I don’t know what the cause of it is. I’m confused. It’s a lot of different feelings going on right now,” she said.

The shooting happened five years to the day when a gunman opened fire during a video game tournament in Jacksonville, killing two people before fatally shooting himself.