Japanese public broadcaster NHK said Wednesday that an erroneous alert about a North Korean missile fired at Japan was sent by a staff member. The staffer meant to transmit a different news flash, NHK said, denying any mechanical flaw, AP reported. The erroneous NHK news flash had been prepared for a possible emergency, the broadcaster said, adding that transmission of an alert usually involves checking by multiple staff members. The false alarm Tuesday came just days after emergency authorities in Hawaii sent a mistaken warning of a missile attack to mobile phones across the state, triggering panic.