Rare footage from inside North Korean factories recently surfaced on social media, showing workers assembling computers and televisions using American and Chinese components in an apparent violation of international sanctions.

Videos shared by a Chinese blogger purportedly showed him visiting Pyongyang for a business trip between Feb. 21-28, where he toured several factories. Workers could be seen in the footage assembling computers, TVs, speedboats, yachts and other plastic materials.

A video uploaded Sunday showed a plastic extrusion machine with markings indicating it was manufactured by the China-based Qingdao Hualide Plastic Extrusion Equipment Co. Ltd.