A deeper focus and uniqueness of quake, prompt actions taken by government officials to displace residents and locals' quake-related knowledge are cited as major causes for less casualties from a recent major southwest China quake.

Shi Shaoxian, a research fellow with the forecast center of theYunnan Provincial Seismological Bureau, said the focus of the earthquake with a magnitude of 6.5 on the Richter scale that had jolted the county of Yao'an on Saturday morning was some 30 km below the ground surface, while the focus of most quakes occurred previously was just 10 km below the surface.

Secondly, an earthquake measuring 5.9 on the Richter scale jolted Yao'an County at 07:37 hours Saturday morning, awakening local residents who rushed out of their houses before a follow-up stronger tremor occurred, Shi said.

Among other reasons, local government officials are perfectly capable of evacuating villagers to safer sites immediately after the first quake.

Moreover, local people know quite well about the rudiments on earthquake and how to protect themselves after the tremor, he added.

Statistics reveal that the quakes left four locals dead, 79 others injured and more than 900 others with slight injuries.