The incident left 11 others injured.

The incident occurred at Madden NFL 19 competition in Jacksonville Landing.

The Jacksonville Sheriff’s Office Twitter said: "#TheLandingMassShooting - Three deceased individuals were located at the scene, one being the suspect. 13 victims -11 with gunshot wounds -2 with other injuries 1suspect deceased."

The gunman, identified as 24-year old David Katz, of Baltimore, Maryland, took his own life inside Chicago Pizza after the shooting, the sheriff was quoted as saying by CNN.

The Sheriff said the attacker at least used one handgun during the incident.

Ryen Alemon, who came from Texas to participate in the gaming tournament, told CNN: "I'm still shocked, I can hardly talk."

Former Congresswoman Gabrielle Giffords condemned the incident and tweeted: "The nation once again looks to Florida with grief and heavy hearts. The massacre in Jacksonville is yet another devastating indictment of this country's inability to keep our kids safe."

Image: Internet Grab