Four construction workers were confirmed dead in a fire in Shanghai's Pudong New Area Saturday, local officials said.

The accident occurred at midnight in a three-story temporary building near the intersection of Yanggao South Road and Chengshan Road, they said.

Firefighters retrieved the bodies of the four workers at about 2:00 a.m.. Other workers managed to escape the fire, but the total number of workers are not known.

Witnesses said the temporary building in which the workers dwelled belonged to Shanghai Dahua Group.

An initiate investigation showed the blaze was caused by a short circuit, firefighters said.