The Work Safety Commission under China's State Council on Wednesday called for an urgent investigation into a fire that has left 20 people dead in Longhua County of the city of Chengde in north China's Hebei province.

In a statement, the commission called on local authorities to determine the causes of the incident as soon as possible, and seriously propose handling as well as rectification measures concerning the incident, based on the findings.

The incident's investigation report will be publicized after it is reviewed and adopted by the commission, it added.

A total of 39 elderly residents were living in the building when the blaze broke out at around 9 p.m. on Tuesday.

The fire was extinguished by about 11 p.m. Twenty people were confirmed dead as of 3 a.m. on Wednesday, while 19 others were sent to hospital for examinations.

The person in charge of the nursing home has been detained by police.