The region suffered a massive earthquake May 12 and since then has been plagued by a heavy rain and a series of aftershocks. The workers were believed to be repairing roads when the mudslide struck.
Earlier, a total of 21 quake-triggered landslides blocked rivers and lakes in the Sichuan province, creating a major risk of flooding and threatening people in downstream areas.
Meanwhile, early on Monday, rescuers pulled two women, aged 50 and 61, who survived 145 hours under the rubble. Both are in a grave condition.
The quake, measuring 7.9 on the Richter scale rattled the southwestern Sichuan province on May 12. At present, a total of 32,500 people have been confirmed dead, but it is feared the death toll will top 50,000. Over 220,000 people have been injured and several thousands are believed to be trapped beneath the debris.
On Monday China declared three days of national mourning, when all national flags in China and its embassies abroad will fly at half mast, public entertainment will be cancelled and the Olympic torch relay suspended.
At 06:28 GMT - the moment the quake struck last Monday - Chinese people nationwide stood in silence for three minutes while air raid sirens, cars, trains and ship horns were sounded in a collective cry of grief. Trade at China's stock and commodities exchanges in Shanghai, Shenzhen, Zhengzhou and Dalian was also suspended.