The buildings were four to five stories tall and located in Dahui village in Wenzhou.
After the accident, the city and county governments immediately deployed a joint emergency response team of police officers, firemen and medical workers, but they had made little progress so far, state-run Xinhua news agency reported.
"The scene is quite chaotic, as if the place had been leveled by an earthquake," a rescuer said.
"We have to work very carefully because the wreckages of the ruined buildings are joined to homes still standing."
Investigators are yet to confirm the cause of the accident, and it has been largely cloudy in Wencheng over the past few days, with no rain, high winds or any extreme weather or geological conditions.