This video was taken in Tianshui, Gansu province (3 mins 23 seconds):
This one was recorded in Meixian, Shanxi province (47 seconds):
Before you brush this off this phenomenon, the USGS has this to say earthquake lights in general:
Q: What are earthquake lights? Are they real?
A: Observations of earthquake lights (EQL), mostly white to bluish flashes or glows lasting several seconds associated with moderate to large earthquakes, have been reported infrequently by observers since ancient times. It wasn't until the phenomenon was captured in photographs, taken during the Matsushiro earthquake swarm in Japan between 1965 and 1967, that the seismological community acknowledged their occurrence. A satisfactory theory to explain EQL, however, has been elusive and is still not agreed upon. Proposed mechanisms include piezoelectricity, frictional heating, exoelectron emissions, sonoluminescence, phosphine gas emissions, and fluid injection (electrokinetics), but the most recent theory suggests that EQL are caused by separation of positive hole charge carriers that turn rocks momentarily into p-type semiconductors.
The Weather Guys from USA Today thinks it was a coincidence though:
I'm a meteorologist and not a geologist or seismologist, but it appears to me to be a circumhorizon arc that was captured in the video. This is an atmospheric phenomenon that occurs around midday, when the sun is high in the sky, as sunlight is refracted by ice crystals in cirrus clouds close to the horizon.
Is there any relationship between the arc and the earthquake? I think not. While meteorology and seismology fall under the same umbrella of earth sciences, rarely does one impact the other. Circumhorizontal arcs are strictly an optical phenomenon in the atmosphere. The fact that they preceded the earthquake was simply coincidence. They are a relatively common occurrence and, I'm sure, precede all kinds of events, both good and bad.