The U.S. military imposed a day-and-night curfew on all its personnel in Okinawa Prefecture, beginning at 7:30 a.m. Wednesday, following recent incidents involving U.S. servicemen such as the alleged rape of a teenage Japanese girl.

No duration has been set for the curfew, designated as a period of reflection. The measure also applies to U.S. military personnel stationed at Iwakuni base in Yamaguchi Prefecture.

It covers not only Army, Navy, Air Force and Marine Corps servicepersons living on and off military bases but also their relatives and nonmilitary staff.

In Tokyo, Chief Cabinet Secretary Nobutaka Machimura said he ''values'' the measures taken by the U.S. military, but noted that further bilateral discussions are needed to work out specific steps to prevent incidents involving U.S. military personnel from occurring.

''I take the decision to impose the curfew and other measures as having significance in their own way as the first step in the serious discussions'' aimed at detailing preventive measures, Machimura told a press conference.

The top Japanese government spokesman added that he has heard that it is rare for the U.S. military to impose a daytime curfew on its personnel.

Military personnel living on bases are basically banned from leaving their base except for occasions related to church, school, the hospital, or their official duties.

Personnel living outside the bases can, in principle, only move between the installations and their homes by private car, taxi or military transport.

U.S. Forces Japan will designate Feb. 22 as a ''Day of Reflection'' for all U.S. military facilities in Japan, setting up a ''Sexual Assault Prevention and Response Task Force'' in an effort to prevent similar incidents.

The U.S. military came under fire after a Marine was arrested for allegedly raping a junior high school girl in the city of Okinawa on the night of Feb. 10. The United States immediately promised to tighten discipline among U.S. soldiers.

But uproar in Japan continued following revelations that a Marine was arrested for drunk driving in the same city and another Marine was arrested for trespassing after he was found passed out on a sofa in a private residence in Nago, Okinawa Prefecture.

==Kyodo