Task: Translation
Input (English): Investigators say they are currently unsure if the blast was purely accidental, or if foul play was involved, as all efforts were initially focused on attempting to locate survivors.
Output (Japanese): 捜査員によれば、最初は生存者の発見に全力が尽くされたので、爆発が純粋に事故なのか、それとも不法行為があったのか現在のところ不確かである。