On October 10, 1946, the Swedish Defense Staff publicly stated, "Most observations are vague and must be treated very skeptically. In some cases, however, clear, unambiguous observations have been made that cannot be explained as natural phenomena, Swedish aircraft, or imagination on the part of the observer. Echo, radar, and other equipment registered readings but gave no clue as to the nature of the objects". It was also stated that fragments alleged to have come from the missiles were nothing more than ordinary coke or slag.