The Chinese State TV company has a new report (in Mandarin) that provides aerial footage of the Gansu landslide site. It is clear from the video that there are in fact two slides. The video is available via the link below (I have removed the embedded video as it played automatically):
Video available here.
The larger of the two slides is shown in this screen capture from the video:
Strangely though neither of these two slides appear to be blocking the valley, as this screen captured image shows:
Does this mean that there is another landslide downstream that is blocking the valley?