The U.N. High Commissioner for Refugees (UNHCR) called on China to protect North Koreans living in the country earlier this year, months before Beijing reportedly deported hundreds of DPRK escapees, a newly released U.N. document shows.

In the letter to the U.N. High Commissioner for Human Rights (OHCHR), the UNHCR called on China to “acknowledge the severity of treatment issued to those returnees who are deemed to have left North Korea illegally.”