The U.S. Secret Service is investigating a mentally unstable Florida man who made multiple verbal threats against President Obama and former president Bill Clinton, both of whom were visiting the state at the time, law enforcement officials tell ABC News.

Federal agents and deputies from the Orange County Sheriff's Office descended on the suspect's apartment complex Thursday, four miles from where Obama was holding a campaign rally at Rollins College in Winter Park.

"They were all over the place with guns drawn, looking for someone," Stanley Saunders, a resident of the apartment complex, told local ABC affiliate WFTV.

The man was quickly taken into custody inside his home and removed on a gurney, WFTV reported from the scene.

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The Secret Service and Orange County police declined to release the suspect's name.

The threat, called into a Veterans Affairs office earlier in the day, was deemed sufficiently legitimate to warrant a swift response, particularly since Obama had not yet left the area, officials said. But he did not attempt to attend the event or get close to Obama and Clinton.

A Secret Service spokesman familiar with the case described the man as mentally unstable and said that he has been hospitalized.

"During the interview with the subject it was determined he was in need of assistance," Orange County Sheriff's department spokesman Jeff Williamson told ABC News. "Deputies transported the subject to the location for the evaluation and turned the case over to the U.S. Secret Service."