Eighteen primary school pupils were buried Thursday when a landslide struck their school in a southwestern Chinese region that was hit by deadly earthquakes last month, state media said.

China's official Xinhua news agency said a classroom building and two farmhouses were buried in the landslide in the village of Zhenhe in mountainous Yunnan province. Besides the children, a villager was also buried.

The students would not normally have been in school this week as China is on a week-long national holiday.

But students at the Youfang Primary School, where the landslide struck at 0800 am (0000 GMT), and elsewhere in the area were in school to make up for lost classes caused by disruptions related to the September 7 quakes.

Zhenhe is in Yiliang county, which was one of the regions worst-hit by the two 5.6-magnitude earthquakes last month.

The state-run China News Service said schools in Yiliang had resumed classes beginning September 25.

"Youfang is one of the schools that has resumed classes. I have no more details," an official at the Yiliang Education Bureau who gave only his surname Zhang told AFP.

An earlier statement by the bureau had said all classes were to resume by October 5.

A family of three managed to escape before the landslide hit, Xinhua said.

Local government officials moved local residents to safer ground after the disaster and dispatched rescue teams to the area, it added.

Last month's quakes left 81 people dead, another 820 people injured, and 201,000 displaced.

Chinese web-users quickly began raising questions about why the pupils were in school.

"Are the officials all on vacation? Why was there no alert? Why were there students in school during the holidays?" said a user of leading portal Sina.com's popular micro-blogging service.

Southwest China is prone to earthquakes. In May 2008, an 8.0-magnitude tremor rocked Sichuan and parts of neighbouring Shaanxi and Gansu provinces, killing tens of thousands.

Many schools collapsed in the 2008 quake, leading to accusations that corner-cutting in construction projects and possibly corruption led to shoddy buildings, especially as many buildings nearby such school held firm.

Domestic media also said after the September quakes that authorities should emphasise safety and sustainability in future developments.

Despite decades of rapidly improving living standards, China remains prone to natural disasters such as floods, quakes, and landslides, with heavy loss of life.