MIAMI (CNN) -- Rescue crews on Tuesday were combing the waters in
                  an area between Puerto Rico and the Dominican Republic for possible
                  survivors after a sailboat carrying dozens of Dominican migrants capsized.

                  Several people were reported to have drowned, according to the U.S. Coast
                  Guard and Dominican Republic Navy, which conducted the search in the
                  Mona Passage, a strait between Puerto Rico and the Dominican Republic
                  connecting the Atlantic Ocean with the Caribbean Sea.

                  Details of how the boat capsized were not immediately clear, but the Coast
                  Guard said as many as 70 migrants may have been on the small boat.

                  The Coast Guard was notified of the accident around noon on Monday by
                  local news media and promptly contacted the Dominican Navy to begin the
                  search.

                  More than a dozen people swam to shore at Uvero Alto Beach, Dominican
                  Republic after the boat took on water. A number of bodies were recovered at
                  the beach by local authorities and a Coast Guard helicopter spotted others in
                  the water.

                  The Dominican Navy has an 82-foot patrol boat searching the waters and the
                  110-foot U.S. Coast Guard cutter Grand Isle is assisting.

                  Earlier, two Coast Guard helicopters, a C-130 Hercules airplane and an
                  HU-25 Falcon jet conducted an aerial search before being called back due to
                  darkness.

                  "Because of visibility, they called off the night (aerial) search," said Jibron
                  Soto, a Coast Guard spokesman.