A recent four-day immigration enforcement operation in Massachusetts swept up 19 illegal immigrants who had either been charged or convicted for drug offenses, authorities say.

According to an Immigration and Customs Enforcement (ICE) news release, those caught in the course of the operation — which was aimed at "criminal aliens who have been convicted or charged with fentanyl, heroin, and other drug-related trafficking crimes" — were from seven different countries.

Those arrested include:

A Cape Verde national with multiple prior convictions for crack cocaine, breaking and entering, possession of cocaine and heroin, and vandalism prison property.

A fugitive alien from Cape Verde with a conviction for cocaine distribution and a previous removal order from 2011.

A Cape Verde national with prior drug and firearms convictions.

A Dominican national facing charges for cocaine trafficking who was removed from the U.S. in 2018 but illegally re-entered.

The release also states that many of those caught in the operation "were released from local law enforcement custody into Massachusetts communities with no notification to ICE."

“ERO deportation officers are committed to enforcing immigration laws fairly and professionally, while protecting the neighborhoods of the Commonwealth,” ICE Enforcement and Removal Operations Boston deputy field office director Todd Lyons said in the release.

“It was all part of an operation to focus on the opioid crisis mainly in Suffolk County,” Lyons told the Boston Herald. He also explained that agents used fingerprint data to help track down the criminal aliens, who "were going back into the city and trying to blend back in.”

Lyons also noted the difficulties of trying to combat a drug crisis while dealing with sanctuary policies that often shield offenders who are getting their supply from Mexican drug cartels: “Many politicians are focusing on the opioid epidemic but not the strategic use of law enforcement that must go along with it."

The extent to which the Bay State's current drug problems stem from illicit drug trafficking is highlighted by a recent study of Massachusetts drug deaths by Boston University associate professor Alexander Walley, which found that just 16.8 percent of opioid-related deaths between 2013 and 2015 involved prescription opioids and just 1.3 percent of those deaths involved people with valid prescriptions. But, as Conservative Review's Daniel Horowitz explained in an article about the Walley report last month, "Massachusetts is a state that is friendlier to criminal alien drug networks than perhaps any other state besides California" due to a combination of sanctuary policies and weak-on-crime enforcement.