The HAARP kind of technology can do a few things beyond mere communications. For example, one can steer high altitude balloons with it by operating on the ionosphere. How this is done is one heats the air in a region and this can push air sideways. It is how the jet stream is manipulated for weather modification. But it can also move balloons, and China undoubtedly has used it for that purpose.

The connection to earthquakes is a bit harder to make but might be done through a chain of effects.