Seoul has warned Pyongyang to stop operating South Korean-owned assets at the Kaesong Industrial Complex, the joint economic project that the South pulled out of in 2016.

The unification ministry issued the statement on Thursday after North Korean state media featured buses that previously operated in the complex. North Korea has used these buses outside the Kaesong premises for years.

“Despite our repeated demand to stop, North Korea continues to illicitly use [our property] in the complex” and Pyongyang “without consent from relevant businesspeople,” the ministry stated in a press release.

This is “a clear invasion of property rights,” and