The collapse of a subway under construction in China has forced the evacuation of dozens of residents after their six-storey building started tilting.

The residents in Guangzhou were forced to flee their homes when the ground above the subway construction site collapsed on Sunday.

The building now has a lean of a neat 2 degrees and might have to be rebuilt.

"If the experts identify the tilted building as dangerous, we will demolish it and build a new one for the residents," Feng Guoguan, construction site boss, told the China Daily.

"If a new building is not possible, we will erect the old one using the latest technologies."

It seems these subway cave-ins are worringly normal in Guangzhou, which has an apparently complicated and fragile geology made worse by underground construction.