At least two people were killed and more than a dozen others wounded, many of them teenagers, in a shooting in the car park of a nightclub in Fort Myers in Florida.
The two people killed were 14 and 18 years old, police have said.
Police found "several victims suffering from gunshot wounds" outside the nightclub. the Fort Myers Police Department said in a statement.
Between 14 and 16 people were wounded, with their injuries ranging from minor to life-threatening.
The club was hosting a "teen night" for people of all ages, CNN reported.
The victims arriving at Lee Memorial Hospital in Fort Myers ranged from 12 to 27 years old, according a statement from spokeswoman Cheryl Garn.
One victim died at the hospital, she said, while three others were admitted, one of them in critical condition.
Police said three people had been detained for questioning and that the area was deemed safe.
Investigators were seeking to determine a motive and the identities of the two people who were killed, the statement said.
UPDATE: 2 dead, as many as 17 people were shot at Fort Myers nightclubhttps://t.co/DMETR1GOHI pic.twitter.com/CqwA6zdj8H
— 10News WTSP (@10NewsWTSP) July 25, 2016
At least 20 cop cars on scene. Working to get info. Believed to be connected to shooting at Club Blu.@Fox4Now pic.twitter.com/eTJRky63TY
— Stephanie Tinoco (@stinocoTV) July 25, 2016
Police said shots were also fired at a nearby residence, where there was one minor injury.
Fort Myers police and the Lee County's Sheriff's Office were canvassing the area for other people who may have been involved, the statement said.
Police have identified the two killed as 14-year-old Sean Archilles and 18-year-old Ste'fan Strawder, who was described by local media as a star high school basketball player.
Police said they could not give a motive for the shooting but said "this incident is not an act of terror (as it has been referred) or terrorism."
The shooting came six weeks after a massacre at a nightclub in the Florida city of Orlando, where a lone gunman who sympathised with Islamist extremist groups killed 49 people in the deadliest mass shooting in US history.
Fort Myers, on Florida's Gulf Coast, is about 240km southwest of Orlando.
