Multiple people have been shot dead in a mass shooting in Florida, the local sheriff's office has said.

Jacksonville Sheriff's Office said one suspect was "dead at the scene" and it was "unknown" if there were any other suspects.

SWAT (special weapons and tactics) teams are searching the area and helping people who took shelter when shots broke out.

The Sheriff's Office warned the public to avoid the area, tweeting that it was "not safe".

The force also tweeted there had been "multiple fatalities", but no definite number has yet been confirmed.

The shooting took place at Jacksonville Landing, a waterfront dining, entertainment and shopping site.

Local media reported that the shooting took place at a restaurant that was hosting a video game tournament.

Video shared on social media showed players competing at a Madden American football game before shots rang out.