The attacker, who is reportedly an employee of the bank, even live-streamed the attack on Instagram.

The victims were aged between 40 and 64. Among nine others injured was a rookie police officer who had graduated to the force just two weeks ago, reports BBC.

The officer's condition still remains critical.

Police responded within three minutes, and fatally shot the attacker in an exchange of gunfire, BBC reported.

The incident occurred in Old National Bank.

Kentucky Governor Andy Beshear mourned the loss of lives in the incident and tweeted: "The death toll from today’s tragic event in Louisville has now risen to five lost. My heart breaks for these families, Louisville and our entire commonwealth. Please join Britainy and me in sending all our love and prayers to everyone affected."

Louisville Mayor Craig Greenberg tweeted: "As this difficult day comes to an end, I’m sad to say that we have lost another life to today’s horrific shooting. Deana Eckert has passed away. Please join Rachel and me in praying for peace and comfort for her and her family."