SANTO DOMINGO, Dominican Republic (AP) _ A boat carrying 40 migrants trying to illegally reach Puerto Rico sank off the Dominican coast, killing at least eight people, the Dominican navy said Monday.

Twenty-one people survived the sinking, and U.S. Coast Guard aircraft and Dominican navy ships were searching for 11 others just off Bavaro, 90 miles east of Santo Domingo. In a prepared statement, the navy said it had arrested the trip's organizer, a man it identified only as William.

The migrants' 40-foot wooden boat had left the town of Sabana de la Mar before it lost one of two small motors and sank in rough weather off Bavaro, Dominican navy Lt. Holguin Terrero said.

Dozens of Dominicans die each year while trying to reach Puerto Rico, a U.S. territory 75 miles to the east. From Puerto Rico, many Dominican migrants hope to make their way to the U.S. mainland.