American Samoa's marine border patrol have stopped an unidentified Samoan fishing vessel from illegally entering the territory.
Under American Samoa's emergency declaration due to the measles epidemic, all vessels entering the territory must obtain prior approval.
Authorities say the alia fishing boat was boarded last Friday and the occupants detained for violating local immigration law.
Homeland Security Director Samana Semo Ve'ave'a said it was important that those entering the territory did so through proper governmental channels.
He said those actions were taken to stop the spread of measles, as well as to prevent human trafficking, drug smuggling and other illegal activities.