OMAHA, Neb. (AP) — Authorities say they have broken up a branch of a Mexican drug cartel dealing methamphetamine in the Omaha area. Police announced Tuesday the arrests of 20 people associated with the Sinaloa drug cartel in Mexico following an 18-month investigation.

The Omaha Police Department and the U.S. Drug Enforcement Agency deployed investigators who received tips that a woman in charge of a sizeable methamphetamine ring was operating near Omaha. The investigation led officials to the source of the supply in California and the discovery of Nebraska and Iowa customers, who bought the methamphetamine and resold it in smaller amounts.

Authorities say they gathered about 12.5 pounds of methamphetamine and more than $35,000. Most are charged with conspiracy to distribute methamphetamine, an offense that could mean 20 years to life in prison.