More than 400 people across the country have been charged with participating in health care fraud scams totaling about $1.3 billion in false billings, including for the prescription and distribution of opioids.

In what federal officials Thursday called the “largest ever health care fraud enforcement action” by the Medicare Fraud Strike Force, 412 individuals, including 115 doctors, nurses and other licensed medical professionals, were arrested in a nationwide operation that involved more than 1,000 law enforcement agents in at least 30 states.

“One American dies of a drug overdose every 11 minutes and more than 2 million Americans are ensnared in addiction to prescription painkillers,” Attorney General Jeff Sessions said at a news conference. “We will continue to find, arrest, prosecute, convict and incarcerate fraudsters and drug dealers wherever they are.”

Sessions said the operation began with tips from people in the affected communities and from “very sophisticated computer programs that identify outliers.”

The investigation particularly focused on medical professionals who were involved in the unlawful distribution of opioids and other prescription narcotics, officials said. The abuse of pharmaceutical opioids is widely blamed for a medical crisis involving tens of thousands of overdoses on heroin and fentanyl.

“Last year, an estimated 59,000 people died from a drug overdose…opioids play an enormous role in that total number,” said Chuck Rosenberg, acting administrator of the Drug Enforcement Administration. “This is an epidemic.”

Approximately 91 Americans die every day of an opioid related overdose, according to the Centers for Disease Control and Prevention.

Among the 412 defendants, 120 were charged with opioid-related crimes. Six of the doctors were charged with operating a scheme in Michigan to prescribe patients with unnecessary opioids, some of which…