Local police allegedly discovered and seized 260,000 kilograms of melamine-tainted milk powder from a local food company at the start of a huge crackdown on Monday night, the website of People's Daily reported on Tuesday.

Three people were detained in connection with the case.

The milk powder was destined to be used by the Chongqing Jixida Food Co Ltd to make ice cream and other foods.

Police officers told the website they intercepted the tainted milk powder and no contaminated products entered the market.

Police said a company from the Guangxi Zhuang autonomous region sold the batch at a price that was obviously lower than market value on March 16.

On Tuesday, more than 10,000 police officers in the municipality began the first full day of a 100-day crackdown against crimes that endanger people through inferior food and medicine, said Zhou Jingping, spokesman for Chongqing municipal public security bureau.

The campaign followed on from Monday night's raids that involved 7,940 police officers at 627 locations and led to the detention of seven people and administrative punishments for 16 others.

Many local people told China Daily they support the Chongqing campaign but some wondered why the effort was to be relatively short-lived and would only last 100 days.

"I hope the police will crack down on those profit-driven businessmen who have lost their morality," said 21-year-old undergraduate student Tang Wenwen from Sichuan Fine Arts Institute. "Otherwise, they could become even bolder in their production of poisonous food."