Russian tankers have supplied fuel to North Korea on at least three occasions in recent months by transferring cargoes at sea, breaching United Nations sanctions, sources told Reuters.
Officials seized the KOTI, a Panamanian-flagged vessel, after it was suspected of illegally selling oil to North Korea, maritime authorities told South Korea's Yonhap news agency.
State outlet Yonhap News Agency reported the ship can carry more than 5,000 metric tons of oil and has a crew mostly from China and Myanmar.
South Korea has seized a Panama-flagged ship suspected of transferring oil products to North Korea in breach of United Nations sanctions, a report said Sunday.
"China will continue to participate in the work of the relevant Security Council sanctions committee on this principle", it said in a short statement, without elaborating.
"The government has been in close consultations with related countries and ministries to thoroughly implement the sanctions by the U.N. Security Council", the spokesman said.
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Four ships - three North Korean vessels and a Palau-flagged oil tanker - were blocked from worldwide ports by the UN Security Council on Thursday over suspicions of carrying or transporting goods banned by sanctions targeting Pyongyang's weapons ambitions, according to the final list adopted by the world body.
The two sources cited naval intelligence and satellite imagery of the ships operating out of Russian Far Eastern ports.
The ship, seized at Yeosu Port on November 24, is suspected of transferring 600 tons of refined petroleum to a North Korean ship named Samjong No. 2.
Both China and Russian Federation are the DPRK's long-standing energy patrons, as North Korea has no domestic oil and gas production of its own. He could not clarify whether they belonged to mainland China or Hong Kong.
China denied Friday that it was supplying oil to North Korea, USA Today reported.
"This marks a typical case of North Korea shrewdly circumventing UN Security Council sanctions by using its illegal networks", he told journalists. The KOTI does not seem to be included on the list.
Additional reporting from Newsy affiliate CNN.