Police and fire teams arrive at the scene outside a FedEx facility in Indianapolis early on Friday. AP

A gunman killed eight people and wounded several others before apparently taking his own life in a late-night attack at a FedEx facility near the Indianapolis airport, police said, in the latest in a spate of mass shootings in the United States after a relative lull during the pandemic.

The incident came a week after President Joe Biden branded US gun violence an "epidemic" and an "international embarrassment" as he waded into the tense debate over gun control, a powerful political issue in the United States. Five people were hospitalised after the Thursday night shooting, according to police. One of them had critical injuries, police spokesperson Genae Cook said. Another two people were treated and released at the scene. FedEx said people who worked for the company were among the dead.

A witness said that he was working inside the building when he heard several gunshots in rapid succession.

"I see a man come out with a rifle in his hand and he starts firing and he starts yelling stuff that I could not understand,” Levi Miller told WTHR-TV. "What I ended up doing was ducking down to make sure he did not see me because I thought he would see me and he would shoot me.”

It was the latest in a recent string of mass shootings across the US Last month, eight people were fatally shot at massage businesses across the Atlanta area, and 10 died in gunfire at a supermarket in Boulder, Colorado.

It was at least the third mass shooting this year in Indianapolis alone. Five people, including a pregnant woman, were shot and killed in January, and a man was accused of killing three adults and a child before abducting his daughter during at argument at a home in March.

Police have not identified the shooter or said whether he was an employee at the facility. They said "preliminary information from evidence at the scene” indicated that he died by suicide.
"We’re still trying to ascertain the exact reason and cause for this incident,” Cook said.

Gov. Eric Holcomb ordered flags to be flown at half-staff until April 20, and he and others decried the shooting, with some noting how frequent such attacks are.
"We wake up once more to news of a mass shooting, this time in Indiana. No country should accept this now-routine horror. It’s long past time to act,” Secretary of Transportation Pete Buttigieg, who is from Indiana, tweeted.

Family members gathered at a nearby hotel to await word on loved ones - and some employees were bused there for tearful reunions. But other relatives said they still had no information about their loved ones hours later. Most employees aren’t allowed to carry cellphones inside the FedEx building, making contact with them difficult.

"When you see notifications on your phone, but you’re not getting a text back from your kid and you’re not getting information and you still don’t know where they are … what are you supposed to do?” said Mindy Carson, holding back tears. Her daughter, Jessica, works in the facility and she had not heard from her.

Associated Press