WEST PALM BEACH, United States: Authorities on Monday charged a man suspected of plotting to assassinate Donald Trump with federal gun crimes, after shots were fired at the former US president's Florida golf course.

Here are five things to know about the incident.

At approximately 1:30 pm time (1730 GMT) on Sunday, a US Secret Service agent noticed the barrel of a rifle pointing out of shrubbery on the Trump International Golf Course in West Palm Beach.

Agents, who were deployed in a moving security bubble one or two holes ahead of the former president, "engaged" an individual, the US Secret Service's Rafael Barros said, with the suspect fleeing.

Trump was "between 300 and 500 yards (meters)" away, Sheriff Ric Bradshaw said.

Police recovered a loaded semi-automatic rifle equipped with a scope, two backpacks, and a GoPro camera from the scene, according to the criminal complaint submitted Monday.

"With a rifle and a scope like that, that's not a long distance," said Bradshaw, referring to the distance between the recovered gun and Trump.

About 45 minutes later, police apprehended a suspect after receiving information from a witness who reported a man fleeing in a black vehicle.

It was identified by its registration information and spotted on the I-95 highway as it entered adjacent Martin County.

Authorities pulled over the car - whose tags belonged to a different, stolen, vehicle - and detained the suspect.

US media reported the man was unarmed and calm when taken into custody.

Phone records showed he had been waiting in the shrubbery overnight, according to the criminal complaint.

Police identified the would-be attacker as Ryan Wesley Routh, whom AFP interviewed in Kyiv in 2022, where he had traveled to support the war effort against Russia.

Routh, 58, is reportedly a builder based in Hawaii, with an arrest record spanning decades and several states.

He regularly posted about politics and current events on social media, including criticism of Trump, US media said.

AFP interviewed Routh two years ago while he was taking part in a demonstration in support of Ukrainians trapped in a city under siege by Russian forces.

"Putin is a terrorist, and he needs to be ended, so we need everybody from around the world to stop what they are doing and come here now," he told AFP at the time.

The incident appeared to be the second assassination attempt on Trump, after an attack at a rally in July that left him slightly wounded in his right ear, with one rally attendee killed.

Since then, Trump has moved most campaign events indoors, and addresses audiences from behind a bulletproof screen.

His Democratic rival Kamala Harris has also taken to speaking from behind a screen.

Trump's political rhetoric has always been aggressive, but his 2024 campaign has increased the temperature, with a focus on the hot-button issue of immigration.

The Republican says there is an "invasion" of migrants, who he alleges - without proof - of being responsible for violent crimes, including murder, rape and robberies, in US cities.

Last week, the Ohio town of Springfield saw bomb threats called in after Trump riled his base against the town's 15,000 Haitian migrant residents, falsely accusing them of eating people's pets.

Sunday's drama brings the spotlight back on the US Secret Service, which is tasked with the security of sitting and former US presidents.

On July 13, a shooter set up on a roof 130 yards from the president and fired at least eight times, raising questions about the Secret Service's competence and resulting in the resignation of the agency's director.

In Florida, the Secret Service had not secured the whole golf course, focusing on a zone around the president, Sheriff Bradshaw said.

"He's not the sitting president. If he was, we would have had this entire golf course surrounded," he said.

"But because he's not, security is limited to the areas that the Secret Service deems possible."

President Joe Biden called for Congress to authorize more personnel for the agency.

"The (Secret) Service needs more help," he told reporters.

  - AFP