Faced with mounting public outrage after a Christmas night fire killed 309 people in a notoriously unsafe shopping centre, Chinese Premier Mr Zhu Rongji yesterday promised "severe punishment" for those responsible.
Police were looking into arson as a possible cause of the fire, which ripped through a popular dance hall on the top floor of the six-storey building in the central city of Luoyang, a local official said.
State media said 20 suspects had been placed under close police watch.
But as grieving relatives identified the remains of their loved ones, public anger focused on the woeful state of China's building safety highlighted by the tragedy.
Xinhua news agency said the building had been warned about inadequate fire-fighting systems since 1997 and that the privately run disco was operating illegally after its licence was revoked.
With Lunar New Year celebrations coming up next month, the Ministry of Public Security issued an urgent notice ordering all discos and dance halls operating without a licence or fire control systems to be closed immediately.
In Shanghai, inspectors visited nightclubs, video game parlours and warehouses, television pictures showed. They ordered locked doors opened, tested emergency fire equipment and instructed workers to clear blocked stairwells.