Rescuers had recovered seven bodies from debris as 10:50 p.m. on Saturday after an under-construction building collapsed on Saturday afternoon in central China's Hubei Province.
In addition, 13 others were rescued and sent to local hospital.
At least 20 construction workers were buried after the four-story building toppled at around 5 p.m. at the Qiuzhigou Village of suburb Wuhan City, the provincial capital, said Wan Yong, mayor assistant of the city.
Wan said it is not clear how many people were at the site when the accident happened as the head in charge of the project ran escaped.
Xinhua reporters saw the building has become a pile of ruins about five meters high and more than 100 rescuers are searching for the missing in rain.
The municipal authorities said the construction of the building, a private residence, is illegal because it had not been approved by the local government.
However, large rescue equipments, such grab and crane, can hardly got into the site because of the small alleyways less than 10 meters in width.
Investigation into the cause of the accident is underway.