SHANGHAI — Chinese 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 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 about increasingly sophisticated counterfeiting operations. The government acknowledged Sunday that the manufacturing of fake drugs had become harder to detect.

Although the government has repeatedly vowed to step up food and drug safety measures and announced the arrests of counterfeiters and the closure of scores of underground operations, scandals seem to resurface every few months. In 2007, the government executed the former head of the food and drug watchdog 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 cardiac arrest.

In a statement, the Ministry of Public Security said it would offer rewards of up to $8,000 to those who help uncover fake drug operations.