Ten people were killed and eight were injured in a deadly fire in Wenzhou, a city in east China's Zhejiang Province, on Friday morning, local police confirmed.

The fire broke out at around 5 a.m. on the sixth floor of the staff dormitory building of Wenzhou Aoji Sanitary Products Co. Ltd. Three workers were killed at the spot, while seven died later after medical treatments failed.

Before the rescue operation, five of the seven who died later were already in critical conditions after jumping from the dormitory building to escape and the other two suffered deadly burns.

The eight injured were sent to a local hospital for immediate medical treatment, with one suffering 30 percent skin burns and another two suffering 8 percent skin burns. The rest who suffered slight injuries have already been discharged from the hospital.

The ten dead were migrant workers from provinces of Anhui, Yunnan, Guizhou and Hubei.

Preliminary investigation shows the fire was a case of arson and the suspected arsonist Wang Yefu, also a worker with Aoji Sanitary Products Co. Ltd, has been detained, said the local police.

The fire has been put out and the motive of Wang's intentional offence remains unknown.