TAMPA, Fla. (WFLA) — The Polk County Sheriff’s Office said it helped confiscate five kilos (11 pounds) of fentanyl, enough to kill about 2.7 million people, in what the agency is calling the largest fentanyl seizure in its history.

The bust, dubbed “Operation Hot Dirt”, involved multiple agencies, including the Florida Department of Law Enforcement, Office of the State Attorney for the 10th Judicial Circuit, U.S Border Patrol, U.S. Department of Homeland Security Investigations (HSI) Tampa Office and the Manatee County Sheriff’s Office.

In September, detectives with the Central Florida HIDTA (High Intensity Drug Trafficking Area) task force learned an international ring had been trafficking multi-kilograms of fentanyl from Mexico to Bradenton and then into Polk County. The fentanyl was manufactured in Mexico and sent into the United States to be made into synthetic pills and sold, authorities said.

Undercover detectives negotiated to buy fentanyl from a supplier in Mexico. Ignacio Rodriguez, 28, of Bradenton, was the local facilitator for the sale, according to deputies. Rodriguez told the detectives they only sold large amounts of fentanyl and that the price fluctuated based on its quality, according to the sheriff’s office.

Undercover detectives seized five kilos of fentanyl during a bust in Polk County. (WFLA)

On Sept. 19, he agreed to meet undercover detectives in Polk County and showed up to the meeting with five kilograms of fentanyl worth $60,000. Two kilos were inside a Cinnamon Toast Crunch cereal box, and the other three were stuffed inside a yellow cooler, authorities said.

Rodriguez warned the detectives they could overdose, and suggested they wear a mask and gloves, and drink milk before ingesting the drug to help relieve the sensation of tightness in the chest. He also offered to sell them marijuana, meth, and cocaine, according to the sheriff’s office.

Rodriguez was arrested in Manatee County on Oct. 14 on charges of trafficking in fentanyl, conspiracy to traffic in fentanyl, possession of a vehicle for drug trafficking, unlawful use of a two-way communication device, and possession of drug paraphernalia.

A photo shows three suspects who were arrested following a historic drug trafficking investigation in Polk County. (WFLA)

The investigation led detectives to two more suspects, Mario Alberto Castro Solache, 29, of Raleigh, North Carolina, and Pedro Mondragon, 27, of Lillington, North Carolina.

Authorities said said Castro Solache drove from North Carolina to Polk County to negotiate another multi-kilogram sale, and was accompanied by Mondragon.

Castro Solache told detectives he planned to move to Polk County to help the cartel establish part of the ring in Polk County, and would be responsible for handling operations.

Both men were taken into custody.

Castro Solache faces charges of conspiracy to traffic in fentanyl. The sheriff’s office said he arrived to the U.S. in May and is in the country illegally.

Mondragon was charged with conspiracy to traffic in fentanyland bonded out of jail on Oct. 17.

“This poison is coming into the country across the border from Mexico, and we are going to continue our investigation into the Mexican drug cartels who are killing innocent people,” Polk Sheriff Grady Judd said in a statement.