NEW BRUNSWICK — More than a dozen people who had previously been held at the Middlesex County Jail were arrested during a sweeping ICE operation that also brought condemnation of county policies from immigration officials.

Thirty-seven people were arrested across Middlesex County during a five-day period last week across the county, with 16 having been previously held in the county jail "without honoring the ICE detainer or advising ICE of their release," a statement from ICE said.

"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," the ICE statement said. "It also overburdens local law enforcement. ICE will continue to execute its mission in such communities."

Discussions of so-called sanctuary cities or counties became more prominent last year when the Trump administration instituted new immigration policies. The "sanctuary" description has no formal definition — but broadly referrs to municipalities or entities that limit cooperation with federal immigration enforcement, sometimes by refusing to honor ICE requests to detain people suspected of being in the country illegally. President Donald Trump last year signed an executive order that would withhold federal funding from "sanctuary jurisdictions."

The arrests included people in the country illegally from Central and South America and as far away as Africa and Asia, ICE said. Those who were previously arrested ranged in age from 21 to as old as 68 and were facing charges of serious crimes including aggravated criminal sexual contact, battery, and domestic violence assault, it said.

The oldest of the people who had been previously arrested and released were a 68-year-old from Mexico who had been arrested in Perth Amboy in 2009 on charges including murder and hindering prosecution, according to ICE. The man was later convicted of aggravated manslaughter and other charges in 2011 and sentenced to 25 years in jail.

He was transferred back to the Middlesex County Jail in 2015 while he was appealing his convictions, and in May of 2015 an ICE detainer was issued, the agency sad. The appeal was successful, resulting in the man being convicted of one count of hindering, and was sentenced to time served. Despite the ICE detainer, the man was released before being arrested again last week, ICE said.

Last June the Middlesex County Board of Freeholders ordered the county sheriff's department to not assist federal immigration deportation matters, and ordered the county jail to ignore requests to hold inmates who might be in the country illegally. The freeholders said the exception to that rule was if they had been convicted of serious crimes.

The policy adopted by the county said it "has and will continue to cooperate with all law enforcement agencies at the local, state and federal levels to ensure the safety of its residents."

Because ICE detainers don't carry the same weight as legal court orders, they have caused problems with local law enforcement agencies across the state. Somerset County Sheriff Frank Provenzano disputed a claim from ICE that his department did not cooperate with federal authorities by releasing an inmate before they could be taken into custody. While the suspect was eventually picked up by ICE, the county was blasted for being uncooperative with the efforts.

In a statement to New Jersey 101.5 on Monday ICE, officials said all detainers issued by the organization are "submitted with an accompanying administrative arrest warrant or warrant of removal depending upon the circumstances of the individual case."

"Middlesex County does not honor ICE detainers, nor do they contact ICE prior to release, sot that ICE can make arrangements to assume custody," the statement said. "These reckless actions put their community ar risk and facilitates criminal aliens in the circumvention of U.S. Immigration law.

A message seeking comment from Freeholder Director Ronald G. Rios was not returned as of Monday afternoon.

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