Monday's earthquake in southwest China's Sichuan Province has left 8,533 people dead, local authorities said.

The figure climbed from 7,651 provided earlier Monday night by the temporary headquarters for disaster relief headed by Premier Wen Jiabao in Sichuan.

The 7.8-magnitude earthquake rocked Wenchuan County, 159 km northwest of the Sichuan provincial capital of Chengdu, at 2:28 p.m. Monday.

At least 30 people were killed in Wenchuan. However, the actual figure is hard to obtain as the county is isolated from the outside world.

Of the estimated death toll in Sichuan, 7,395 people are feared dead in Mianyang City to the northeast of Chengdu.

In Mianyang's Beichuan County, 160 km northeast of Chengdu, the number of deaths is estimated at more than 3,000, as 80 percent of the buildings were destroyed by the quake.

Sources with the headquarters said casualties are being tallied in other areas affected by the massive quake, and detailed information is being collected on the damage.

The number of casualties is expected to rise as further destruction is reported. Authorities are yet to reach Wenchuan County, which sits at the epicenter of the earthquake with a population of about 112,000.

Li Chongxi, deputy secretary of Sichuan Provincial Committee of the Communist Party of China, led a rescue team to Wenchuan, but was stranded at Dujiangyan City.

"We are doing everything we can, but the roads are blanketed with rocks and boulders," Li said.

Rescuers were clearing the debris to reach the quake-hit sites as quickly as possible, he said. Telecommunications links to the county had also been cut.

The powerful earthquake was also strongly felt in may other parts of the country, including Beijing and Shanghai.

In northwestern Gansu Province, at least 48 people were killed and in Shaanxi Province, at least 61 were killed, according to local authorities.

专题：四川汶川发生7.8级强地震>>