FORT MYERS, Fla. (AP) — A shooting at a Florida nightclub early Monday morning killed two people and wounded at least 16, police said. The attack apparently occurred at a teen party, billed as a “Swimsuit Glow Party,” at Club Blu in Fort Myers, according to local media.

Police detained three people and said the area around the club had been deemed safe, police Capt. Jim Mulligan said in a statement.

It was not immediately clear what triggered the violence.

Four people remained hospitalized Monday morning, including two in the intensive care unit, Cherly Garn, a spokeswoman for Lee Memorial Health System, said in an e-mail. All others were treated and released. A shooting victim brought to Cape Coral Hospital was also treated and released, Garn said.

Ages of the patients ranged from 12 to 27, Garn said.

The shooting comes more than a month after a nightclub shooting in Orlando that was the deadliest shooting in modern U.S. history. The shooting at the Pulse nightclub on June 12 left 49 victims dead and 53 others wounded.

The violence at Club Blu erupted about 12:30 a.m. Monday, Mulligan said. There were two active crime scenes, police said. Several hours later a street in the area remained closed as police investigated.

The area was later deemed safe, but Mulligan said a street was still closed as authorities investigated.

In a statement, authorities said the Fort Myers police and the Lee County Sheriff’s Office were “actively canvassing the area looking for other persons who may be involved in this incident.”

The names of the victims were not immediately available.

A post on Club Blu’s Facebook page Monday morning said the shooting happened as the club was closing and parents were picking up their children. The post also said there was armed security at the event.

“We are deeply sorry for all involved,” the post read. “We tried to give teens what we thought was a safe place to have a good time.”