The China Earthquake Administration on Sunday upgraded the devastating Sichuan earthquake to 8.0 on the Richter scale, following an earlier rating of 7.9 by international seismologists, the dpa reported.
Chinese experts had previously given a magnitude of 7.8 to the quake, which claimed at least 32,500 lives and left thousands of others missing under collapsed buildings.
Leading international seismologist Gary Gibson on Friday told Deutsche Press-Agentur dpa that the Sichuan quake was so destructive because the epicentre was shallow and it took place in the middle of a continent.
Gibson said its destructive power was comparable to that of the 9.1-magnitude earthquake in December 2004 off the coast of Sumatra, which killed at least 158,000 people in the resulting tsunami.
He said no significant precursory seismic activity was detected that could have allowed the Chinese government to issue a clear warning before the Sichuan quake.
"I had nothing unusual at all that you would regard as precursory," said Gibson, who works at the Seismology Research Centre at Monash University in Melbourne, Australia.
"There were not even moderate events," Gibson said of the period before Monday's quake.