According to the US Coast Guard, a commercial tanker spotted the capsized boat on December 6 off the Dominican Republic, near the island of Saona.
The boat was carrying 28 migrants, of whom the tanker rescued 21. The remaining seven are missing.
According to sources, the migrants are believed to be Dominicans who were going to the nearby US territory of Puerto Rico.
When then incident occurred, the Dominican authorities called the US Coast Guard for helpt after the boat was spotted on Thursday.