The U.S. Navy has banned its personnel on all bases in Japan from drinking alcohol at night as part of efforts to enforce stricter discipline in response to a series of crimes by U.S. military personnel.

U.S. Naval Forces Japan spokesman Cmdr. Kenneth Marshall was quoted by wire services as saying that active-duty sailors are now prohibited from drinking alcohol from 10 p.m. to 8 a.m., even in their homes, regardless of leave or liberty status.

Officers at the Sasebo naval base in Nagasaki Prefecture confirmed the ban has been imposed on all 3,100 service members stationed there.

An 11 p.m.-5 a.m. curfew was imposed on all service members in October after two U.S. sailors were arrested on suspicion of raping a local woman in Okinawa.

Even with the curfew in place, a drunken U.S. Air Force airman allegedly entered an apartment in Yomitan, Okinawa, and hit a teenager in the face, and a sailor in Yokohama was arrested last week for alleged public indecency during curfew hours.

In Sasebo, a U.S. sailor was found dead on a station platform in late October. He had been electrocuted, apparently by touching an overhead power line after climbing onto the roof of a stationary train after drinking.