An illegal lab in Mexico produced some of the powerful painkiller that killed dozens of people in Chicago last year who ingested with heroin, according to newly unsealed indictments.

Two drug conspiracy indictments unsealed Thursday name 13 people in Mexico and seven members of Chicago's Mickey Cobras street gang.

Gang members were accused of getting the painkiller, fentanyl, mixing it with heroin and selling the combination in city public housing complexes, killing at least five people. Nationwide, hundreds have died from heroin laced with fentanyl since 2005. In Cook County, officials attributed more than 200 deaths to fentanyl-laced heroin.

The new charges mark the first time law enforcement has been able to link the Mexican laboratory in Toluca to drug sales in Chicago. Last year, federal prosecutors in Chicago charged 47 gang members and associates with selling heroin and the painkiller fentanyl in public housing.

Mexican authorities shut down the lab last year.

Six of the 13 from Mexico who were indicted, including the alleged ringleader, are awaiting extradition. The seven Chicagoans include that gang's alleged leader. Some of the defendants could face life in prison if convicted, said Assistant U.S. Attorney Jake Ryan.

Frank Limon, chief of the Chicago Police Department's organized crime division, said the charges marked a successful cooperation between city and federal authorities.

"Today's indictment reached across our borders to Mexico and indicted the alleged head of a drug trafficking organization," Limon said Thursday. "This shows what can be accomplished when federal and local agencies combine their efforts."