U.S. Immigration and Customs Enforcement agents arrested 37 people who were in the United States illegally during a five-day law enforcement operation in Middlesex County.

ICE says that the raid “targeted criminal aliens who were previously incarcerated at the Middlesex County Jail, and who were subsequently released to the community…without honoring the ICE detainer or advising ICE of their release.”

The agency says that of the 37 people arrested, 16 had previously been released by the jail without notifying ICE. About 78 percent of those arrested had prior criminal convictions or pending criminal charges, according to ICE.

Ruben Perez, acting field office director of Enforcement and Removal Operations (ERO) in ICE's Newark office, criticized Middlesex County leaders for being a so-called “sanctuary county.”

“ERO New Jersey will continue to enforce ICE’s commitment to public safety,” Perez said in a statement. “Middlesex County, which aspires to be a ‘sanctuary county’ by protecting criminal aliens, in the process assists criminals in undermining federal law, and creates a dangerous environment in the community. It also overburdens local law enforcement. ICE will continue to execute its mission in such communities.”

ICE did not release the individuals’ names but say that they ranged in age from 21 to 68 years old and were nationals of Brazil, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, India, Ivory Coast, Mexico, Nigeria, Peru and Turkey.