A total of 31 people, including local officials, have been punished over the collapse of a gypsum mine in northern China that killed 33 people, state media reported Saturday.

Sixteen officials including Dai Zhanyin, vice mayor of Xintai city in Hebei province, face warnings, demotions, dismissal and prosecution for breaching production safety rules, the Xinhua News Agency said.

The mine's owner, Zhang Yukui, and 14 employees were also charged with negligence, Xinhua said.

The Kangli mine collapsed in November 2005, damaging two other nearby gypsum mines and toppling a two-story building. The accident killed 33 people and injured 40.

Investigators found that the three mines were operating illegally after being told to shut down for a safety overhaul, Xinhua said.