North Korea started dismantling power lines installed north of the shared border with the South from Sunday in the latest of a series of demolition of past inter-Korean peace efforts.

According to South Korea’s Joint Chiefs of Staff on Tuesday, the North Korean military was spotted taking down power transmission systems on its side of the Military Demarcation Line dividing the Korean Peninsula.

The JCS said the North Korean military was cutting off high-voltage wires from the power transmission towers that deliver electricity to Kaesong Industrial Complex in the North’s border city.

The KIC opened in 2004 as a joint project intended to increase economic cooperation and reconciliation, before Seoul closed it down in 2016 following Pyongyang’s rocket launch.

“The North Korean military took down high-voltage wires from one of the power towers closest to the border. These are properties that South Korea financed and built,” JCS spokesperson Col. Lee Sung-jun told reporters.

North Korea in October blew up inter-Korean roads connected to the South. The South’s JCS at the time explained that the explosion was not destructive enough to destroy anything beyond the surface of the roads, seeing the move as largely symbolic.

The South Korean military believes the cross-border aggression is a continuation of North Korean leader Kim Jong-un threatening to abandon the traditionally shared goal of unification, and declaring inter-Korean relations to be one of two hostile countries.