YAN'AN - An overheated stove was found to have caused the fire in a commercial building in northwest China's Shaanxi Province on Saturday, local authorities said Sunday.

Three people died and 21 others were injured in the fire which occurred at about 4:30 am Saturday, according to the Yan'an municipal government.

Firefighters try to extinguish a fire that broke out in a commercial building in Yan'an, Northwest China's Shaanxi province, Dec 22, 2012. [Photo/Xinhua]

An initial investigation showed that the fire broke out from a stove, used by a construction team to keep the temperature for concrete pouring in their reinforce work for the 14-story World Trade Building in downtown Yan'an on early Saturday morning, the government said.

The worker who should take care of the smokeless coal stove, went out without asking for a leave. The overheated stove ignited quilts and cloth at the site, the government said.

Ten people of the construction company were under police control, waiting for further investigation.

The three victims included a security guard of the building, a staff member of a restaurant and a hotel guest.

The 21 injured people including a 7-year-old child are all in a stable condition, according to the government.