Three people were killed on Saturday after a gunman opened fire and targeted Black people at a Dollar General store in Jacksonville, Florida.

“This shooting was racially motivated and he hated Black people,” Jacksonville Sheriff T.K. Waters said at a news conference, as quoted by CNN.

Waters said the shooter, who he described as a White man in his 20s, shot and killed himself after the attack.

The suspect left behind what the sheriff described as three manifestos outlining his “disgusting ideology of hate” and his motive in the attack, added Waters.

All three victims were Black.

Waters said the shooter lived in Clay County, Florida, south of Jacksonville, with his parents, and told his father by text to “check his computer.” The father found documents described by Waters as manifestos and called authorities.

The shooting started shortly after 1:00 p.m. ET, blocks away from Edward Waters University, a historically Black school where students living on campus were told to stay in their residence halls.

Jacksonville Mayor Donna Deegan said the gunman barricaded himself inside the store after the attack. It was not immediately clear if victims were shot inside or outside the store.

Deegan told local news station WJXT, "This is unacceptable. One shooting is too much but these mass shootings are really hard to take."

Florida State Sen. Tracie Davis, whose district includes Jacksonville, called the shooting a “tragic day” for the city in a post on Twitter.

“I’m offering prayers to the families of the victims and am on my way to meet with (Jacksonville Sheriff T.K. Waters) for answers,” Davis wrote.

“This type of violence is unacceptable in our communities,” she added.