Authorities said that they have found no terrorist connection to three men stopped along Alligator Alley in South Florida.
A law enforcement official in Washington said that the three men appear to be medical students going to a medical conference in Miami.
The official said the men's nationalities are Jordanian, Iranian and Pakistani, and at least two are naturalized U.S. citizens.
A Florida law enforcement source said that the men received medical training at Ross University on the Caribbean island of Dominica. The source said they were heading to Larkin Community Hospital in Miami for training. The official said none of the men were on any watch lists. Both officials spoke on condition of anonymity.
Gov. Jeb Bush also said that there isn't a terrorist threat. The men were in two cars on Interstate 75. The Interstate across South Florida was shut down all day, and authorities blew up a backpack, apparently suspecting it contained explosives.