Dujiangyan, May 13:

Bodies covered with sheets lined streets today as rescue workers dug through schools and homes turned into rubble by China’s worst earthquake in three decades in a desperate attempt to rescue victims trapped under concrete slabs.

The official death toll rose to more than 12,000 in Sichuan province alone, with thousands remained buried or missing.

But hope that many survivors would be found was fleeting. Only 58 people were extricated from demolished buildings across the quake area so far, China Seismological Bureau spokesman Zhang Hongwei told the official Xinhua News Agency.

In one county, 80 per cent of the buildings had been destroyed.

A day after the powerful 7.9 magnitude quake struck yesterday afternoon, state media said rescue workers had reached the epicentre in Wenchuan county - where the number of casualties was still unknown. The quake was centred just north of the Sichuan provincial capital Chengdu in central China, tearing into urban areas and mountain villages.

Rain was impeding efforts and a group of paratroopers called off a rescue mission to the epicenter due to heavy storms, Xinhua reported.

While Wang gave the death toll as 11,921, Xinhua later said more than that had been killed in Sichuan alone.

In Mianyang city alone near the epicentre, 3,629 people were dead and 18,645 were still buried in debris, Xinhua reported. At least 4,800 people also remained buried in Mianzhu, 100 km from the epicentre, Xinhua said, citing local authorities.

Difficulties in accessing some areas meant the numbers of casualties remained uncertain and were expected to rise due to problems in finding buried victims.

Aftershocks rattled the region for a second day, sending people running into the streets in Chengdu. The US Geological Survey measured the shocks between magnitude 4 and 6, some of the strongest since yesterday’s quake.

Elsewhere in Gansu province, a 40-car freight train derailed in the quake that included 13 gasoline tankers was still burning today, Xinhua said.

Premier Wen Jiabao, who rushed to the area to oversee rescue efforts, said a push was on to clear roads and restore electricity as soon as possible.

His visit to the disaster scene was prominently featured on state TV, a gesture meant to reassure people that the ruling party was doing all it could.

Expressions of sympathy and offers of help poured in from the United States, Japan and the European Union, among others.

The Dalai Lama offered prayers for the victims.