They say CCTV systems are necessary to prevent thefts which drain companies and can drive them out of business.
Trial of two women accused of killing Kim Jong Nam resumes after nearly three months.
Families hold onto remains, including uniforms and dog tags, found on battlefields across the country, sources say.
The teens, many of them students, work 12-hour days for half of what adult coworkers earn, sources say.
Numbers of those kidnapped differ in North Korean and Japanese statements, and some may still be held.
Sources say the reduced monitoring has facilitated the smuggling of restricted goods.
Prime Minister commends North Korean leader’s “new attitude,” calls for pursuing good relations with Pyongyang.
North Korea merely reaffirms an earlier commitment to denuclearizing, with no specific timetable.
US President Donald Trump and North Korean leader Kim Jong Un make history by meeting, but doubts hang over any nuclear deal.
Authorities want to prevent possible disorder inside the isolated country during the key talks in Singapore.
Controls by China relax after Kim Jong Un and Xi Jinping meet in March and May.
The letter comes five days before US President Donald Trump meets with Kim Jong Un in Singapore.
State Security agents are pressuring family members to convince their relatives to return home.