More than 200 Chinese relief workers have been buried under mudslides, as it emerged that 70,000 people may have lost their lives in last week's earthquake.

Two construction machines and six vehicles were also submerged over the last three days as emergency workers struggled in difficult conditions.

It is understood that the relief workers were buried while trying to repair damaged roads, but it is not yet known how many - if any - have been pulled to safety.

The incidents came as the government announced that 70,000 people are feared dead, buried or missing after the 7.9 magnitude quake tore through the south west region of Sichuan last week.

Official figures for the number of people killed in the natural disaster stand at 32,000, but tens of thousands more are still missing and more than 200,000 people are believed to be injured.

The Chinese government announced three days of mourning to remember those who have died, and the country came to a standstill to observe a three minute silence.

Flags flew at half-mast at 2.28pm local time (6.28am UK time) to mark the moment the quake struck a week ago.

Several thousand people gathered in Tiananmen Square in central Beijing, standing silently around a flagpole from which the red Chinese flag waved.

The Beijing Olympic torch relay that had been making its way through China has also been halted for three days.

Although hopes were fading that any more survivors would be found, two women were pulled out of the rubble alive nearly a week after the quake struck.

Li Lingcui, 61, was conscious when she was rescued in Beichuan county, one of the worst-hit areas, at around 10.40am local time (2.40am UK time). Xinhua news agency said she had an infection and many broken bones.

Wang Fazhen, 50, was pulled out from under a collapsed residential building of a coalmine at Hanwang in Deyang city an hour later.