Police deploy at the scene of a mass shooting near Slugger Field baseball stadium in downtown Louisville, Kentucky, on Monday. Reuters

The shooting, the 15th mass killing in the country this year, comes just two weeks after a former student killed three children and three adults at a Christian elementary school in Nashville, Tennessee, about 260 kilometres to the south. That state's governor and his wife also had friends killed in that shooting.

Police in Louisville arrived as gunshots were still being fired inside Old National Bank and exchanged fire with the shooter, Louisville Metro Police Department Deputy Chief Paul Humphrey said at a news conference. He said it wasn't clear whether the shooter killed himself or was shot by officers.

"We believe this is a lone gunman involved in this that did have a connection to the bank. We’re trying to establish what that connection was to the business, but it appears he was a previous employee,” Humphrey said.

Two people embrace outside of a building where a shooting took place in Louisville. AP

Nine people, including two police officers, were treated for injuries from the shooting, University of Louisville Hospital spokeswoman Heather Fountaine said in an email. One of the officers was in critical condition, she said. At least three patients had been discharged.

An emotional Kentucky Gov. Andy Beshear said he lost friends in the shooting in the building on East Main Street not far from the Louisville Slugger Field and Waterfront Park.

"This is awful,” he said. "I have a very close friend who didn’t make it today. And I have another close friend who didn’t, either. And one who’s at the hospital that I hope is going to make it through.”

It was the second time that Beshear was personally touched by a mass tragedy since becoming governor.

In late 2021, one of the towns devastated by tornadoes that tore through Kentucky was Dawson Springs, the hometown of Beshear’s father, former two-term Kentucky Gov. Steve Beshear. Andy Beshear frequently visited Dawson Springs as a boy and has talked emotionally about his father’s hometown.

Beshear spoke as the investigation in Louisville continued and police searched for a motive. Crime scene investigators could be seen marking and photographing numerous bullet holes in the windows near the bank’s front door.

Associated Press