Beijing, China: More than 20 people were buried under rubble after four houses collapsed in China on Monday, a local government and state media reported.

The buildings caved in during the early hours in Wenzhou in the eastern province of Zhejiang, the Lucheng district government said in a statement.

The Xinhua news agency said on social media that an ‘initial estimate’ was that more than 20 people had been buried.

The Lucheng government said six people had been rescued, without giving indications of the missing. The cause of the collapse was under investigation, it added.

Pictures from the scene showed workers in orange suits sifting through a mountain of ruins.

China has also 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.

Two people were killed and 24 injured in April when a storm brought down a wholesale market building in Foshan city, in the southern province of Guangdong.