## Context ##

In [China urges citizens in N. Korea to return home][1]:

> The Chinese Embassy in North Korea has advised Korean-Chinese
> residents to return home amid concern that the North's military
> provocations may trigger a U.S. attack on the North, according to a
> source.
> 
> The embassy began sending the message on Apr. 20, five days before the
> North celebrated the 85th anniversary of the Korean People's Army with
> a show of military power, Radio Free Asia said Tuesday.

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## Why I'm asking ##

It is clear that it is illegal for Freedom of Movement for North Korean people to leave as stated in [The People’s Challenges][2].

> **No Freedom of Movement**
> 
> It is illegal for the **North Korean people to leave their country
> without the regime’s permission**, and the regime attempts to restrict
> the people’s movement even inside their own country. If you wish to
> travel to another part of the country, you are supposed to have a
> specific purpose and obtain permission from your work unit. If you do
> not live in Pyongyang, the showcase capital where most resources are
> concentrated, you will likely be denied access. The regime has also
> forcibly relocated hundreds of thousands of North Koreans to less
> favorable parts of the country as a form of punishment and political
> persecution.
>
> *(emphasis mine)*

and also by [Human Rights Watch in their World Report][3]

> The government uses threats of detention, forced labor, and public
> executions to ensure obedience and imposes harsh restrictions on
> freedom of information and movement. It criminalizes leaving the
> country without official permission, and **in some instances state
> security services actively pursue North Koreans into China**, seeking to
> detain and forcibly return them. 
>
> During Kim Jong-Un’s rule, the
> government has significantly expanded efforts to **stop irregular
> crossings of North Koreans into China.** The government has increased
> rotations of North Korean border guards, cracked down on brokers who
> assist people trying to leave, and **prosecuted use of Chinese cell
> phones to communicate with the outside world**. North Koreans who left
> the country in 2014 and 2015 told Human Rights Watch that the
> government was tracking down and publicly executing border guards who
> allowed people to cross into China in exchange for bribes.
>
> *(emphasis mine)*


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Question
--------

Does China have an agreement/policy (being [N Korea's biggest ally][4]) for such actions to take place (if so, *what is it*?) or would they have to escape?


  [1]: http://www.koreatimes.co.kr/www/nation/2017/05/103_228651.html
  [2]: http://www.libertyinnorthkorea.org/learn-nk-challenges/
  [3]: https://www.hrw.org/world-report/2016/country-chapters/north-korea#3cd65b
  [4]: http://www.newsweek.com/china-north-korea-trump-allies-economy-583883