At least three Russian oil tankers transferred fuel to North Korean ships in recent months, in violation of U.N. sanctions, Reuters reports. It is unclear if these alleged transfers occurred with the knowledge of the Russian government. Two of the alleged transfers occurred in October, with a third in November. Russian ships allegedly left Pacific Ocean ports and switched off their transponders to evade tracking in open waters. Russian shipping sources told Reuters that the ships were meeting with North Korean vessels and transferring fuel ship-to-ship or via fishing boat. On Thursday, President Donal Trump accused China of smuggling oil to North Korea, but the White House has not commented on these latest allegations against Russia.