The presidential campaign team of Donald Trump reported "gunshots in his vicinity," with the FBI later saying it was investigating a possible assassination attempt.
Shots were fired near Donald Trump, his team reported on Sunday, in the US state of Florida.
The FBI said it was invesitgating the incident.
"The FBI has responded to West Palm Beach Florida and is investigating what appears to be an attempted assassination of former President Trump," the agency said in a statement.
Rifle and camera recovered from scene
US Secret Service agents identified and fired on a suspect training a weapon on part of the Trump International Golf Course in West Palm Beach early in the afternoon, authorities said in a press conference later on Sunday.
"We are not sure right now if the individual was able to take a shot at our agents," said Rafael Barros of the Secret Service.
The suspect is said to have fled in an SUV and was later detained in nearby Martin County by local law enforcement.
"We have somebody in custody right now that is a potential suspect," Palm Beach County Sheriff Ric Bradshaw told a press conference.
Bradshaw said the suspect was hiding in the bushes, situated about 400 to 500 yards (356 to 457 meters) away from Trump, while he played golf on a nearby hole.
Secret Service agents, who protect US presidents and presidential candidates and other dignitaries in the States, had been scouting ahead of the former president on a security sweep when they engaged the suspect.
Police in Palm Beach found an AK-47 assault rifle with a telescopic sight and a GoPro camera in the bushes at the scene, Bradshaw said.
Source: DW