South Korean authorities seized a second oil tanker for allegedly supplying fuels to North Korea at sea, the South’s media reported on Sunday.

The announcement is the second of its kind this week, further highlighting the of use of ship-to-ship cargo transfers banned by UN resolutions.

South Korean officials are holding the 5100-tonne, Panama flagged tanker called KOTI in Pyeongtaek-Dangjin after deciding not to release the vessel on December 21 to investigate further.

The seizure follows that of the Lighthouse Winmore, another oil tanker which Seoul claims supplied fuel products to North Korea in October, in breach of UN Resolution 2375.