MIAMI (AP) _ Waves swamped an overloaded Haitian sailboat as Coast Guard crewmen were trying to transfer the passengers to their cutter, and two people may have drowned in the confusion, authorities said Tuesday.

The cutter Thetis arrived in Port-au-Prince Tuesday with the remaining 48 people aboard, and the Coast Guard has launched an investigation into the incident, said Lt. Cmdr. Jeff Karonis.

The sinking occurred Sunday afternoon when the Thetis intercepted the 30- foot sailboat about 400 miles southeast of Miami.

After U.S. Immigration and Naturalization Service determined the passengers were illegally attempting to enter the United States, the Coast Guard distributed lifejackets and began transferring the Haitians to the cutter.

''A large wave caused the Haitian vessel to capsize and sink, throwing the Haitians, the Coast Guard boarding party and the INS agent into the water,'' a Coast Guard release said.

Four Haitians were injured - one was cut and three nearly drowned - and passengers reported two others were missing.

But because the boat carried no passenger list, the Coast Guard could not determine if the report was accurate, the release said.

A search was conducted, but no sign of the two was found, Karonis said. At the time of the accident, winds were 10 knots with seas of 5 to 7 feet.