The quake, measuring 7.8 on the Richter scale, was the worst to hit the country in more than three decades, and affected eight provinces, with Sichuan suffering the bulk of the devastation. Around 80% of buildings have been destroyed in some areas.
The official death toll in Sichuan has been confirmed at 19,500, the Xinhua news agency said earlier on Thursday. Some 64,000 people are hospitalized, with over 13,000 of them severely injured.
China has stepped up military rescue efforts in 58 counties and towns ravaged by the quake, with more than 130,000 troops engaged in the ongoing relief operation. A total of 20 helicopters have been dispatched for reconnaissance, food and water airdropping, and an additional 60 helicopters are planned to be sent.
More than 5,500 people had been rescued from the rubble as of 8:00 a.m. (midnight GMT) on Thursday. Around 25,000 people are believed to still be trapped under collapsed buildings. More than 9 million people have been evacuated from the affected areas.
Authorities fear that the death toll could rise, and the national meteorological center is warning that more tremors could occur.
Some 14,000 people are said to be unaccounted for near the epicenter of the quake, some 60 miles (96 km) northwest of Sichuan's provincial capital, Chengdu. Deaths have also been reported in neighboring Shaanxi and Gansu provinces.
The government has allocated over $160 million in emergency aid for the quake-hit areas, while Chinese citizens have donated over $120 million in the past two days to help the disaster victims.
Russian rescuers have flown to China to assist the relief operation. A third Russian transport plane is expected to arrive in China on Thursday. Russia sent two aircraft carrying a total of 60 tons of humanitarian aid to China on Wednesday.
