BEIJING (Reuters) -Sixteen people were killed in a fire at a department store in Sichuan province in China's southwest on Wednesday evening, state media said on Thursday.

The fire broke out in a 14-storey building in a high-tech zone of the city of Zigong, shrouding the vicinity with thick smoke, according to the Xinhua news agency.

Overnight rescue work ended at 3:00 a.m. (1900 GMT on Wednesday), state broadcaster CCTV said.

Preliminary investigation showed the fire was due to construction operations. Further investigation was underway to identify the specific cause of the fire.