A little girl protected by the embrace of her dead father was the last survivor pulled out of the rubble of collapsed multi-storey buildings in China, reports said Tuesday.

She was found deep in the debris of four six-storey residential buildings more than 12 hours after they crumbled in Wenzhou in the eastern province of Zhejiang, killing at least 22 people, state broadcaster CCTV said.

Three-year-old Wu Ningxi survived with only minor injuries thanks to the protection offered by her young father, who was found dead after shielding her from falling rubble, it added.

"The child was able to survive entirely thanks to the fact that her dad used his own flesh and blood to prop up a life-saving space for his daughter," a rescuer told the China Youth Daily.

The 26-year-old shoe factory worker was found under a thick cement pillar, draped over his daughter.

The family had been buried alive in their living room and the body of Wu's mother was discovered not far from the pair.

Photos showed hard-hatted rescuers lifting the girl's half-naked body from the mess of cement and fallen bricks late Monday, her hair matted with dust as they carried her out and gingerly placed her onto a stretcher.

The search through the three-storey-high debris concluded early Tuesday, the Lucheng district government said at a press conference, with 22 confirmed dead and only five survivors other than the girl rescued.

The cause of the disaster was still under investigation, CCTV said.

Recent heavy rainfall combined with the poor quality of construction and age of the buildings, built by the villagers themselves, were probable contributing factors, it cited a preliminary analysis as saying.

Neighbouring buildings constructed in the 1970s were being demolished to prevent further collapses, the official Xinhua news agency reported.

The buildings had been packed with migrant workers, among them Wu's parents, hundreds of millions of whom have moved from China's countryside to its towns and cities in recent decades, their labour fuelling the country's economic boom.

Many remain poorly paid and face restrictions on buying homes in the areas where they work.

China has seen several building collapses in recent years, with some blamed on low-quality construction.

In May 16 people were reported dead after a residential building in Guizhou province in the southwest collapsed due to landslides.