Washington  - US President George W Bush on Monday expressed condolences to the victims of a 7.8-magnitude earthquake that left several thousand dead in China's south-western province of Sichuan.

"I extend my condolences to those injured and to the families of the victims of today's earthquake in China's Sichuan Province. I am particularly saddened by the number of students and children affected by this tragedy," Bush said in a statement.

He said the US is prepared to offer aid.

The confirmed death toll rose to at least 7,651, but no figures had been reported from some affected areas, the official Xinhua news agency quoted provincial officials as saying.

The dead included at least four teenagers after the earthquake caused school buildings to collapse and bury nearly 900 students at the Juyuan Middle School in Sichuan's Dujiangyan city, about 100 kilometres from the epicentre, reports said.

Earlier reports quoted officials as saying an estimated 3,000 to 5,000 people were feared dead in Sichuan's Beichuan county alone.

By late Monday evening there were still no reports from Wenchuan county, the nearest town to the epicentre, which which has a population of 112,000. (dpa)