SAN DIEGO (AP) — Federal authorities have indicted 26 people and seized nearly 500,000 counterfeit pills laced with fentanyl during a two-year investigation into an international drug smuggling operation, prosecutors announced Tuesday.

Charges of conspiracy to traffic drugs and possessing drugs with intent to distribute were filed against 26 people. Seventeen defendants, most of them from San Diego and surrounding areas, have been arrested and the others are being sought, the U.S. attorney's office announced.

If convicted, they face 10 years to life in prison and up to a $10 million fine each, prosecutors said.

The drug trafficking operation, based in Sinaloa, Mexico, shipped counterfeit pharmaceutical pills laced with fentanyl, powder fentanyl, heroin, methamphetamine and cocaine to the United States, prosecutors said.

The investigation involved various federal, state and local law enforcement agencies.

“As fentanyl continues to fuel the ongoing opioid epidemic and claim ever more lives, we will use every available resource to find, apprehend, and hold accountable those who seek to profit from it, no matter where they are.” Randy Grossman, U.S. attorney for the Southern District of California, said in a statement.