Orange County Police said on Monday that the attacker also killed himself, adding that the situation has been contained.
Several roads in Orlando, where the shooting took place, were closed as officers responded to the incident, according to the Associated Press news agency.
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The focus of the investigation is on a business that makes roof and shade for recreational vehicles.
Authorities said officers of the Federal Bureau of Investigation have joined in the probe.
The incident happened almost a year after the 2016 Orlando nightclub shooting that left 50 people dead including the shooter.
Source:Aljazeera/English