Story highlights Spokeswoman: The Dutch ship was going to pick up a U.S. Coast Guard helicopter

The Dutch sailors gave those rescued to U.S. Coast Guard, continued to Key West

Those rescued are "suspected migrants," according to the U.S. Coast Guard

A search continues for 2 others who may still be in the waters off West Palm Beach

At least three people died and seven others were rescued Thursday after their boat capsized off the coast of southeastern Florida, the U.S. Coast Guard said.

And that toll -- of the dead and rescued -- may rise: The Coast Guard believes that two more people may still be trapped or in the Atlantic Ocean, spurring an intense search for them.

A Dutch naval vessel, the Zeeland, heading toward Key West, Florida, first alerted the U.S. Coast Guard at noon about the ship.

Specifically, the Coast Guard said, the Dutch sailors reported seeing "a capsized 24-foot center console vessel with seven suspected migrants atop the hull."

The Dutch sailors rescued those individuals and retrieved three bodies "from within the hull," according to the Coast Guard.

The Coast Guard has since sent the Cutter Richard Etheridge , a 154-foot ship based in Miami, to search for the two missing people. In addition, a C-130 airplane out of Clearwater, Florida, has been dispatched to the scene.

Upon arrival, they took over the operation from the Dutch navy and will transport those rescued to the Florida mainland, Coast Guard Petty Officer Sabrina Laberdesque told CNN.

CNN first learned of the incident via that agency's Twitter account

The Zeeland left the Netherlands 12 days ago en route to the southern tip of Florida, said Lt. Maartje Van Der Maas, a spokeswoman for the Royal Netherlands Navy in the Caribbean. The Dutch sailors will pick up a Coast Guard helicopter in Key West to use over the next four months in drug interdiction operations in the Caribbean.

After handing over the rescued people Thursday, the Zeeland continued onto Key West, according to Van Der Maas.