A school boy was rescued after 80 hours trapped in the rubble of a collapsed school building in southwest China's Sichuan province, hit by a powerful quake Monday, local media said on Friday.

The massive earthquake measuring 7.8 on the Richter scale led to the destruction of many school buildings with over 6,000 classrooms destroyed. In one school alone 300 children were killed when a three-storey building collapsed burying over 850 pupils in Qingchuan.

The death toll from the quake could soar to over 50,000, the country's State Council said on Thursday. The official death toll stands at 20,000 with thousands still trapped beneath the debris.

The high rate of collapsed school buildings has forced Chinese authorities to order a comprehensive inquiry into the state of the region's educational facilities.

According to media reports, buildings most affected by the quake are built of bricks and concrete blocks, while safer modern schools and institutions, such as those in Beijing and Shanghai, are made of steel and concrete.

According to reports from the disaster area, faint cries can still be heard from the rubble and there is hope that more survivors will be saved.