Monday's quake was the worst to hit the country in more than three decades and affected eight provinces, devastating buildings and infrastructure, leaving thousands of people buried alive under rubble.
The bulk of the fatalities were reported in China's southwest province of Sichuan.
Early Tuesday morning a total of 1,180 aftershocks were registered in the disaster-hit province, with the most powerful measuring 6 on the Richter scale.
The China Earthquake Networks Center said other strong aftershocks were likely to follow.
The number of foreign nationals reported missing has risen to 18, including 15 British tourists, two Americans and a Thai national, Xinhua said.
However, the official spokesman for the Chinese Foreign Ministry Qin Gang said no information on foreign casualties was available.
The Russian Embassy in Beijing said they have received no reports of any Russians being caught up in the earthquake. Embassy officials said that Russian nationals were "unlikely" to be in the disaster area.
