Quote:MIAMI, Florida (CNN) -- Security at the Port of Miami was tightened Sunday after three people tried to drive a truck into a secure area without the proper documentation, police said.
The incident began at about 8 a.m., when the driver of the 18-wheeler, which was loaded with cargo, was unable to produce required paperwork, said Robert Williams, a spokesman for the Miami-Dade Police Department.


When the driver was taken from the truck and interviewed, "some of his actions determined that something might not be correct here," Williams told reporters.


Conflicting accounts by authorities make it unclear whether the two were in the container portion of the vehicle or just in the cab portion, behind the driver.


Williams said the parties were detained and interviewed by the FBI.)


A bomb squad was sent "as a precaution" to check the vehicle, he said.


Port of Miami spokeswoman Andrea Muniz said the cargo area was closed.


But Williams said neither the passenger nor the cargo side of the port was closed.


Williams said the three are from the Middle East.


A law enforcement source told CNN the incident does not appear to be related to terrorism. Law enforcement officials told CNN the three appear to be in the United States legally.


Though Williams said no charges had been filed, the FBI said the three were being held on state charges.


Sunday is typically a busy day for cruise ships at the port: Passengers come ashore in the morning and new passengers arrive for late afternoon departures.


<b>Federal law enforcement authorities described two of the three, including the driver, as being of Iraqi descent and the other as being of Lebanese descent.</b> But Williams said their nationalities had not been determined.