In the first incident, a Cessna 152, entered the restricted airspace just before noon yesterday near the Palm City resort where Obama is staying, according to Army Lt. Col. Mike Humphreys.
The military's North American Aerospace Defense Command sent a F-16 fighter jet and a Coast Guard helicopter to intercept the plane, he was quoted as saying by CNN.
The F-16 flew with the plane until it landed at Witham Field in nearby Stuart, where it was met by local officials. The Secret Service and the Federal Aviation Administration are investigating the incident.
Five hours later, F-16s intercepted a Lancair 320, a smaller craft that seats two passengers, the defense command said.
That plane left the restricted airspace after the fighter jets arrived and "continued to its destination,¿ according to the defence command.
Small aircraft occasionally enter areas restricted temporarily when the American president travels. A year ago, a Cessna 182 aircraft was intercepted over Obama's airspace in Los Angeles.