North Korea imported more sanctioned goods, food and hair for wig production from China in September, NK Pro analysis of customs data shows, as bilateral trade jumped to a nearly four-year high last month.

U.N. Security Council resolutions prohibit member states from supplying items under HS Codes 72 through 89 to North Korea. The codes cover categories such as iron, steel and other metals, industrial machinery and transportation vehicles.

But the DPRK significantly ramped up imports of goods falling under these codes in September, with the total coming to $853,509, according to data from China’s General