China's agriculture authority has closed poultry farms where birds were given excessive amounts of antibiotics like amantadine and ribavirin to help them survive in overcrowded coops.
Poultry farms in east China's Shandong province triggered nationwide concern about food safety after reports about the antibiotics, Xinhua reported.
Bi Meijia, spokesman for the agriculture ministry, said Tuesday that such poultry raisers and processors have been shut down and are under investigation.
The Chinese public is sensitive to food and drug safety, and scandals related to tainted milk powder, fake cooking oil and toxic capsules have harmed the credibility of food producers in the country.
Foreign fast food chains have also been embroiled in such scandals. The Shanghai Food and Drug Administration said the level of antibiotics found in chicken samples from an international food chain was fine, but it found a suspicious level of an antiviral drug in the samples.