North Korea has begun dismantling a key testing facility for its missile engines and rocket launches, according to a new analysis of satellite imagery released Monday.

Imagery taken from Friday to Sunday indicates that the North had started to disassemble portions of its Sohae Satellite Launching Station, the country's main satellite launch facility since 2012, according to an analysis published by 38 North, a prominent North Korea monitoring group.

Most notably, it said, these include the rail-mounted processing building — where space launch vehicles are assembled before moving them to the launchpad — and the nearby rocket engine test stand used to develop liquid-fuel engines for ballistic missiles and space launch vehicles.