A 45-year-old ex-employee armed with a handgun and a large hunting knife fatally shot four men and a woman before turning the weapon on himself in a multiple murder-suicide at an Orlando, Fla., business Monday morning, police say.

The incident occurred just after 8 a.m. ET at Fiamma Inc., a business that manufactures awnings for campers and recreational vehicles.

Jerry Demings, sheriff for Orange County, identified the gunman as John Robert Neumann Jr., who was discharged from the U.S. Army in 1999.

Demings earlier told reporters it wasn't yet clear how Neumann Jr. was able to enter the premises. At least eight employees were unharmed and were interviewed by police.

Three men and a woman were pronounced dead at the scene, with another male dying later at a local hospital.

Demings said it was a workplace shooting spree with no apparent ties between the gunman and any "subversive" or terrorist groups.

"My experience tells me that this individual made deliberate thought to do what he did today. He had a plan of action," the sheriff said. "We have information that at least one of [the victims], he had a negative relationship with. He was certainly singling out the individuals he shot."

"Most of the victims were shot in the head; some were shot multiple times," the sheriff added.

Law enforcement authorities said there were 'multiple fatalities' following a Monday morning shooting in an industrial area near Orlando. (John Raoux/Associated Press)

That comment was likely designed to calm a community that on June 12 will mark the grim first anniversary of the fatal shooting of 49 at the city's Pulse nightclub. Omar Mateen, the shooter in that case, was described by some as a "homegrown extremist" who sought out radical Islamist information online and was disruptive at a local mosque.

Fiamma has multiple warehouses on Forsyth Road and Hanging Moss Road, the sheriff's office said earlier. The victims and the shooter were found at various locations inside the premises.

Gunman told another employee to leave

Neumann Jr. was fired in April and was accused of assaulting a male colleague in 2014. Police responded to that incident, but no charges resulted.

The alleged victim in that incident was not one of those killed on Monday, Demings said, and no other employees on scene were injured.

Shelley Adams said her sister, Sheila McIntyre, called her from the company's bathroom during the shooting and was upset.

She kept repeating "My boss is dead. My boss is dead," Adams said.

Police were called by a woman who ran from Fiamma, saying the gunman had told her to leave. She used the phone of a tile business across the street to call 911, said Yamaris Gomez, the tile store's owner.

Florida Gov. Rick Scott responded to Monday's shooting with a statement on Twitter: "Over the past year, the Orlando community has been challenged like never before. I have been briefed by our law enforcement officials on this tragic incident, and [my wife] and I are praying for the families who lost loved ones today."

In addition to the Pulse massacre, the city has more recently dealt with other well-publicized incidents of violence.

In January, a weeklong manhunt ensued for a man accused of shooting area police officer Debra Clayton dead. Markeith Loyd was eventually arrested, and is also a suspect in a homicide involving his pregnant ex-girlfriend, Sade Dixon.

Last week, a man was arrested at the city's airport after a standoff at Orlando International Airport. Police said Michael Pettigrew, 26, was armed with a fake gun and requested to speak to U.S. President Donald Trump.

When asked to try to connect the incidents of violence on Monday morning by a reporter, Orange County Mayor Linda Jacobs said the situations were "very different," but that citizens should always be vigilant in contacting police if they suspect someone is threatening to commit acts of violence.

Officials were waiting for notification of next of kin before releasing the names of the victims.