The government has vowed to overhaul the country's milk collection system to prevent contaminated milk from reaching food-processing plants.

The General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) has already sent 1,644 teams and 387 working groups across the country to inspect the production process of dairy plants.

Melamine-contaminated baby milk food has killed four infants and left more than 53,000 with various urinary tract problems, including kidney stones. About 13,000 infants are still being treated for complications in hospitals, and the condition of 104 is serious. About 40,000 other children have either recovered or are convalescing.