The incident happened at Club Blu in Fort Myers
The two people killed in a shooting at a Florida club were aged 14 and 18, according to police.
17 others were injured - including one person as young as 12.
The shooting took place outside Club Blu in Fort Myers in the early hours of Monday morning, said Lt Jim Mulligan of the Lee County Sheriff's Office.
Three people have been detained by police.
The incident is thought to have taken place during a 'teen night' at the club.
One witness said that she heard around 30 gunshots from the scene and believes they came from a number of weapons.
At least 20 police officers attended the scene and roads in the area were sealed off.
The shootings happened at 12.30am local time.
A police statement said: "The Fort Myers Police Department and Lee County Sheriff's Office are actively canvassing the area looking for other persons who may be involved in this incident.
"At this time the scene is still very active as investigators and crime scene personnel attempt to determine what occurred."
The mass shooting comes more than a month after an attack on the Pulse nightclub in Orlando in Florida. Forty nine people were killed on June 12th, and another 53 were wounded.
This woman spoke about how her daughter almost got shot, while her best friend was not so lucky.
Syreeta Gary's daughter almost got shot at Club Bleu. Her best friend wasn't so lucky. pic.twitter.com/5A3bA1EfBy— Malcolm Johnson (@Malcolmsmedia) July 25, 2016