Police say they have detained four migrants in a northwest coastal area commonly used by people from the Dominican Republic to get into this US territory.
Officers said they detained a man and a woman yesterday afternoon aboard a 28-foot wooden boat with an outboard motor just off an area beach. They said another man and a woman were detained at a nearby landing area on the beach.
The travellers' country of origin was unknown.
Authorities say the four people will be turned over to US Border Patrol officials for processing.
Thousands of Dominican migrants try to cross the dangerous Mona Passage every year in an attempt to land in Puerto Rico.