DENVER – Thirty people from two different suspected drug rings have been indicted for drug trafficking in Colorado, including a woman accused of being the leader of a Mexican ring based in Denver that allegedly sold fetanyl disguised as prescription opioid pills, federal officials said Wednesday.

The alleged leader, Candelaria Vallejo-Gallo, a Mexican citizen living in the United States illegally, was charged with operating a continuing criminal enterprise, a crime which is more commonly referred to as being a “drug kingpin,” said Jason Dunn, the U.S. Attorney for Colorado.

Twenty-seven other people who allegedly worked for her operation, accused of selling methamphetamine, cocaine and heroin, were indicted. Two other people who allegedly trafficked methamphetamine in Adams County north of Denver as part of another enterprise were also indicted.

Of the 30 people charged, 24, including Vallejo-Gallo, have been arrested, and one was in state custody on another charge. Four are believed to be in Mexico, and one is at large in the United States, the U.S. Attorney’s Office said. Vallejo-Gallo’s lawyer did not return a message seeking comment about the allegations.

Most of the more than 15,000 fentanyl pills seized by investigators were made to look like prescription oxycodone, which Dunn said is a growing concern for law enforcement.

“Had these pills reached the street thousands of unwitting users would have been at significant risk of overdose and death as we have already seen too much of lately in Colorado,” he said.

Vallejo-Gallo’s operation allegedly moved its profits from drug sales in Colorado to California and from there to Mexico through couriers unrelated to the movement of the drugs, according to the indictment. In Mexico, the ring allegedly used its money to buy real estate in Tepic in the state of Nayarit to put its assets out of reach of U.S. authorities, the document said.