KUALA LUMPUR, Malaysia—The confusion and frustration that punctuated the investigation into the disappearance of Malaysia Airlines Flight 370 erupted anew Thursday after officials offered conflicting levels of confidence on whether a piece of a wing found washed up on an Indian Ocean island last week came from the vanished plane.
Malaysian Prime Minister Najib Razak’s announcement in the pre-dawn hours of Thursday that the part, known as a flaperon, did indeed come from the doomed aircraft was at odds with the message from authorities in France, the U.S. and Australia, who have stopped short of full confirmation.