China has removed about 25,000 tons of tainted milk powder as of February, a Chinese Health Ministry official said Tuesday.

Chen Rui, an assistant director of the Ministry of Health's Food Safety and Health Inspection Bureau, said that 25,000 tons of melamine-tainted milk powder have been destroyed as of February.

Chen said the discovery last month of more tainted milk powder in Qinghai and Jilin provinces shows that the government needs to improve monitoring and enforcement.

"The abrupt reoccurrence of this type of incident shows that we need to continue to step up our efforts in this work," Chen told a news conference. "Food safety incidents must be thoroughly investigated and the perpetrators must be severely punished."

He said the latest cases were still being investigated.