A South Korean ship is being held at a domestic port over suspicions that it illegally provided oil to heavily sanctioned North Korea, Seoul officials said Wednesday. A South Korean coast guard official said Wednesday the 5,160-ton P-PIONEER has been prevented from leaving Busan port since October over allegations that it was used to supply oil to North Korea through two ship-to-ship transfers in September 2017 in international waters in the East China Sea. He said the ship transferred diesel, but did not confirm how much was supplied. An official from Seoul’s Foreign Ministry said it was the first time a South Korean ship was detained over allegations of violating United Nations Security Council Sanctions against North Korea over its nuclear weapons program. South Korea is also detaining three foreign vessels for illegally providing oil to North Korea or transporting North Korea-produced coal. Both officials spoke on condition of anonymity, citing department rules preventing them from speaking to the press. The UN Security Council in a report last month said North Korea was continuing to defy its resolutions through a “massive” increase in ship-to-ship transfers of petroleum products and coal.