The U.S. Coast Guard is searching in the Florida Straits for a second day for four missing Cubans. 22 Cubans have been brought aboard a U.S. Coast Guard cutter, but four others are still missing in waters south of Key West.

The Cubans apparently were being ferried to the United States by smugglers using so-called "go-fast" boats that can cross the Florida Straits in a matter of hours. But at least one boat capsized in rough seas and torrential rains, throwing 28 people into the water.

Wednesday, a commercial freighter notified the Coast Guard that crewmembers had heard cries for help about 30 kilometers south of Key West. Coast Guard spokesman Michael Brock says search and rescue efforts have been ongoing since then. "We currently have the Coast Guard cutter 'Seneca' on scene, along with a helicopter," he said. "They are continuing to search the area to locate one woman and three children that are still missing. We have 22 migrants on board the 'Seneca' who were rescued [Wednesday]."

The survivors are 18 adults and four children. The body of one man has been recovered; another body was spotted but then disappeared from view.

U.S. immigration authorities are interviewing survivors, but their fate remains unclear. Except in rare cases, the United States repatriates Cubans intercepted at sea, but allows those who reach U.S. soil to stay.

Coast Guard officials say the loss of life illustrates the need to crack down on migrant smuggling operations, which have increased in recent years and often end in tragedy.