All U.S. service members in Japan have been ordered not to leave base unless accompanied, particularly at night, under a new "Buddy Program" following a series of damaging misconduct cases.

The measure ordered by Lt. Gen. Salvatore Angelella, commander of United States Forces Japan, took effect Friday. In principle, it requires all U.S. military personnel stationed in the country to be accompanied by someone — such as a colleague or family member — whenever they leave base outside the recently imposed curfew from 11 p.m. to 5 a.m.

The Buddy Program, the latest initiative to improve discipline, covers around 40,000 U.S. service members in Japan. The specific details of the measure will be left to each base and facility to decide for the time being, including time frames, the official said Friday.