An American who discovered an aircraft part in Mozambique that may be from missing Malaysia Airlines Flight 370 says he initially thought it was part of a much smaller plane.

Blaine Gibson, who has been searching the region's beaches for the debris, said Thursday in an interview with The Associated Press that a boat operator who took him to a sandbank named Paluma called him over after seeing a piece of debris with "NO STEP" written on it.

Gibson says the discovery happened after he decided to go "somewhere exposed to the ocean" on the last day of a trip to the Mozambican coastal town of Vilankulo.

Flight 370 disappeared two years ago with 239 people aboard. The plane is believed to have crashed somewhere in the southern Indian Ocean.