Police said the attacker was arrested.

At 12:40 p.m., two members of the Highlands County Sheriff’s Office TAC Unit arrived on scene and, along with other deputies and officers from the Sebring Police Department, established a perimeter, police said.

The HCSO SWAT team entered the building, where the suspect had barricaded himself inside, to attempt to check on victims.

Crisis Negotiation Team members, along with dispatchers and SWAT members, persuaded the suspect to surrender, the police said in a statement. 

The names and ages of the victims have not been released. They were the only five people in the bank at the time.

The suspect has been identified as 21-year-old Zephan Xaver from Sebring. The investigation into his motives his still ongoing.

"We've suffered significant loss at the hands of a senseless criminal doing a senseless crime," Sebring Police Chief Karl Hoglund to CNN.

It is not clear whether the killed people are bank employees or customers.

They were the only five people in the bank at the time, police said.

“This has been a tragic day for our community. We’ve suffered a significant loss at the hands of a senseless criminal doing a senseless crime,” Sebring Police Chief Karl Hoglund said in a statement.

“This is something that you hope will never happen anywhere, much less in your hometown. We will continue to investigate and work to see that the victims and their families are taken care of and that they receive the justice they deserve," he said.

Sheriff Paul Blackman said: "I am heartbroken that this horrendous incident has occurred in our county.”