KEY WEST, Fla. (AP) — Four Cuban migrants swam to shore in the Florida Keys and three others were rescued from the ocean after their boat sank Wednesday, shortly before Hurricane Ian made landfall in southwestern Florida. But 20 more people might be missing, officials said.

The four Cubans reached Stock Island, just east of Key West, and reported their vessel sank because of inclement weather, U.S. Customs and Border Protection Chief Patrol Agent Walter N. Slosar said in a post on Twitter.

The U.S. Coast Guard initiated a search for 23 people and managed to find three survivors about two miles (three kilometers) south of the island chain, officials said.

The survivors were taken to a local hospital for symptoms of exhaustion and dehydration.

Air crews continued to search for the remaining migrants.