The fire also injured 24 people, the Xinhua news agency reported, citing police.

The deaths were a reminder that even in Beijing, rural migrant workers can live in sweatshop conditions starkly at odds with the city's image of secure prosperity.

City leaders rushed to the scene, where close to 200 firefighters and police put out the flames.

The early morning fire engulfed a four-storey building in Daxing District, an area in the south of Beijing crammed with small factories, workshops and crumbling apartments rented by migrant workers.

An official described the building as an ‘illegal dwelling’. The first floor, where the fire appeared to have broken out and where all the deaths occurred, was rented out for a garment workshop, with a workers' dormitory at the back.

Reuters