A Christian NGO was on Friday stopped by local South Korean police and residents from sending bibles and aid to North Korea from a West coast border area.

The Seoul-based Voice of the Martyrs Korea’s (VOMK) plan to float the aid into North Korea in bottle-shaped containers followed a warning by Kim Jong Un’s sister on Thursday to South Korean authorities to stop activists from sending “anti-DPRK leaflets.”

After the Ministry of Unification (MOU) responded by sayingit was “taking measures to stop the sending of leaflets,” VOMK said South Korean police warned they would deploy one-hundred officers