Blocking suspected vessels from ports - except in the case of humanitarian need - is provided for under UN Security Council sanctions resolutions targeting North Korea over its nuclear and missile programs. According to the list seen by AFP, the ships in questions are the Palau-flagged oil tanker Billions 18, and the North Korean vessels Ul Ji Bong 6, Rung Ra 2 and Rye Song Gang 1.
The North Korean oil tanker Sam Jong 2 so far has not been banned from international ports, but it appears on a list of six ships suspected of transporting cargo banned under the international sanctions.
Copyright Agence France-Presse, 2017