The Memorial Hospital in Jacksonville, Florida, treats at least three patients who were involved in the game, says the spokesman for the hospital, Pete Moberg, CNN.
All of the patients are in stable condition, Moberg said.
Preliminary reports indicate that at least 11 people were shooting at the Jacksonville gaming tournament said a law enforcement officer who was briefed on the incident.
Four of the people shot were killed, the source reported.
Note : This information is tentative and therefore subject to change. We will update when we learn more.
Electronic Arts – the digital interactive entertainment company producing and sanctioning the Madden video game The Jacksonville tournament on Sunday – made a statement on his Twitter account.
"This is a terrible situation, and our deepest sympathies go to all concerned," the company tweeted.
Here is the complete message:  15 minutes ago
Gaming CEO: Player shot in the thumb, but he'll be fine
Jason Lake, founder and CEO of CompLexity Gaming, was just making a statement about the condition of one of her players injured during today's shooting at the Madden 19 tournament.
The player was hit by shots and ran to a nearby gym for safety reasons.
Read his full explanation:
"We are obviously shocked and saddened by the events of this afternoon. Our player Drini was hit with his thumb, but he will be fine, he managed to escape and He ran the street to a nearby gym and is currently working with the authorities and we will have him fly out of Jacksonville as soon as the officers give us the green light on the ground. "
CNN has recorded a video that seems to capture the moment shots were fired while the tournament was broadcast online.
The video caught the sound of about a dozen shots and screamed.
Warning this video could be troubling for some viewers:
Florida Gov. Rick Scott tells Florida Department of Law Enforcement staff responds to the Madden tournament shooting in Jacksonville
He said he had contact with the Jacksonville Sheriff's office.
The Sheriff's Office of Jacksonville said officers find many hiding places in the entire landing zone where the mass shootings take place  The office urged anyone who hid to stay calm and stay in their hiding places.
In a second tweet, the sheriff's office asked every hunter to call 911.
Malik Brunson was at a nearby Hooters when the shootings started at the GLHF Game Bar in Jacksonville, Florida.
"I was in Hooters, all I heard was that he had a gun and the shooting started," Brunson told CNN. "One of the men ran gunshot in Hooters – they locked us up in the restaurant."
He shared the following Facebook photo:
The spokesman for the Jacksonville Sheriff's Office said a suspect was in place Shooting dead.
It is unclear whether there is a second suspect, but deputies search the area.