Chinese government authorities have detained nearly 2,000 people as part of a nationwide crackdown on the sale of fake or counterfeit drugs and health care products, according to a report on Sunday from Xinhua, the official news agency.

The government said that it had mobilized more than 18,000 officers in recent weeks to break up drug counterfeiting rings and that officials had seized about $182 million in fake medicine, including fraudulent drugs for the treatment of cancer, hypertension and diabetes.

The crackdown comes amid growing concerns about the prevalence of counterfeit drugs and tainted food supplies in China, and increasingly sophisticated counterfeiting operations. The government acknowledged Sunday that the manufacturing of fake drugs had become harder to detect. Earlier this year, the authorities in Zhejiang Province, not far from Shanghai, discovered that hospital workers were saving old packages, including those of high-end medications, and reselling them to drug counterfeiters to refill with fake drugs.

In May, the authorities announced the arrest of 200 people accused of making and selling fake drugs. The government has said many of the fake medicines were being marketed on Internet sites, giving counterfeiters a way to sell directly to consumers.

Although the government has repeatedly vowed to step up food and drug safety measures and announced the arrests of counterfeiters and the closing of scores of underground operations, the scandals seem to resurface every few months. In 2007, the government even executed the former director of the food and drug watchdog agency for failing to properly supervise the marketplace.

The recent crackdown comes because of concern that some of the fake treatments are leading to liver damage and even cardiac arrest.

In a statement released Sunday, the Ministry of Public Security said that it would offer rewards of about $8,000 to those who help uncover fake medicine operations.