BEIJING - Local courts in Shanxi and Hebei provinces in northern China convicted and sentenced 14 people on Friday for producing or selling tainted milk powder.

Among the 14 involved in four tainted milk cases, two received life imprisonment, four received sentences of 10 to 15 years in prison, while the rest received lighter sentences

The Intermediary People's Court in Jinzhong city of Shanxi province sentenced Li Baosheng to life imprisonment and confiscated all his personal properties, for blending melamine-tainted milk powder into his own products.

Qi Weigang, who sold Li 11.31 tonnes of melamine-tainted milk power, was also sentenced to life imprisonment.

By July 2010, authorities had seized altogether 173.17 tonnes of tainted milk powder produced by Li, worth 4.415 million yuan (about $671,000), including 130 tonnes that he had already sold, valued at more than 3.317 million yuan.

The local court of Weichang county in Hebei sentenced Zhao Chunfeng, general manager of Yuquan Dairy Company in Chengde City of Hebei, to 15 years imprisonment and fined him 1.37 million yuan, for selling the recalled tainted milk powder after changing their packages and  producing shoddy milk powder.

The court of Zhangbei county in Hebei sentenced Dai Wenming to 7 years in jail and fined him 851,200 yuan, for selling 38 tonnes of recalled melamine-contaminated milk powder in May 2010.

The court also sentenced Sun Xuefeng to 10 years imprisonment and fined him 1.25 million yuan for buying Dai's powder and reselling it to others.

The court of Zhaoxian county in Hebei imposed a fine of 400,000 yuan on Yukang Dairy Company Ltd. of Shijiazhuang city for concealing 30 tonnes of melamine-tainted milk powder during a government crackdown campaign and selling the products later on.

Yang Hengzhu, the company's manager, was sentenced to six years in prison and was fined 200,000 yuan.

The open trials came three years after melamine-contaminated milk powder killed at least six babies and sickened 300,000 others across China.

Chinese leaders have recently called for stern punishments and open trials to those who produce or sell inferior products.