The U.S. Coast Guard said five people were in custody in Fort Pierce after officials got information that undocumented migrants were coming ashore, WPTV reported.
At 5:38 a.m., officials responded to an alert just south of the Fort Pierce Inlet in the 2000 block of South Ocean Drive.
The Coast Guard said the five people claimed to be Cuban. Meanwhile, five others were not found.
Authorities also reported an 18-foot boat was adrift.