SHANGHAI -- A Shanghai high-rise apartment fire that killed 53 people was completely avoidable, Chinese top labor safety official said, blaming lax supervision and illegal work practices.

Luo Lin, head of the State Administration of Work Safety, is leading the probe into the blaze, which gutted the 28-story building Monday afternoon after sparks from welding allegedly set nylon netting and scaffolding on fire, leaving many trapped in their homes.

"The accident should not have happened and could have been completely avoided," Luo saidin comments published Thursday.

Till Wednesday, official report said there had identified 26 of the 53 bodies taken from the building, suggesting many others were not yet identified as family members searched for more than 30 people reportedly missing from the blaze.

Related readings:  Dampening the fire danger  Fire equipment sales skyrocket in wake  Govt order to beef up fire-control measures  Illegal work practices behind Shanghai fire  Shanghai fire teaches a lesson

Officials have not said how many they believe are unaccounted for, although Shanghai's fire chief said the building had been thoroughly searched after the fire was extinguished.

Police said they had detained eight people suspected of responsibility for the disaster, four of them unlicensed welders.

Apart from poor worker safety and supervision, illegal use of subcontractors was a key factor behind the disaster, Luo said, promising to prosecute those responsible.

Police in northeast China's Jilin province, meanwhile, have detained 14 people suspected of involvement in a fire at a shopping mall that killed 19 people earlier this month, Xinhua reported.

Those in custody include managers, fire control directors, welders and security guards at the five-story mall, where a fire originally thought to have been sparked by an electrical problem raged for 12 hours on November 5.

The fire has heightened concern over the ability to cope with fires in high-rise buildings. Shanghai alone has 15,000 high-rise buildings, many of them apartments. On Wednesday, officials ordered tighter fire prevention measures nationwide.