Agents from U.S. Immigration and Customs Enforcement (ICE) “raided” a business in Newark in an effort to detain unauthorized immigrants, according to the mayor of New Jersey’s largest city. Details of Thursday’s operation carried out by ICE were not immediately available, including when or where it took place. It was also unclear whether any arrests were made or if any individuals were taken into custody, though multiple people were allegedly detained, including U.S. citizens, said Mayor Ras Baraka. “[ICE] agents raided a local establishment in the City of Newark, detaining undocumented residents as well as citizens, without producing a warrant,” the mayor said in a statement. “Newark will not stand by idly while people are being unlawfully terrorized.” Baraka noted that one of those who was detained is a U.S. veteran “who suffered the indignity of having the legitimacy of his military documentation questioned.” The mayor called the operation “egregious” and said it violated the Fourth Amendment of the Constitution, which clarifies “the right of the people be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” In a statement, ICE said that agents “may encounter U.S. citizens while conducting field work and may request identification to establish an individual’s identity as was the case during a targeted enforcement operation at a worksite today.” The spokesperson said it was part of an active investigation, and “per ICE policy, we cannot discuss ongoing investigations.” The state attorney general’s office declined to comment, but multiple local officials weighed in with their anger. “Warrantless searches, jackbooted thugs, veterans detained. After pardoning violent insurrectionists, Trump orders ICE agents to detain and harass innocent people, including a veteran who served our country. This is the reality of Trump’s reign of terror, but it’s not the America generations have fought for,” said Rep. Bonnie Watson Coleman. Fellow Democratic Rep. LaMonica McIver, whose district includes part of Newark, said her office was in contact with the Department of Homeland Security “to get answers on exactly what happened, and how it was allowed that ICE came in—without warrant and without justification—to detain not only immigrants, but citizens and even a veteran of our nation’s military.” In a joint statement, New Jersey’s senators Cory Booker and Andy Kim said they were “concerned” about the operation, saying such events “sow fear in all of our communities — and our broken immigration system requires solutions, not fear tactics.” Actions by ICE agents were expected to target major sanctuary cities immediately after President Donald Trump’s inauguration. Within their first few days in office, the administration began setting groundwork for further immigration actions.  The Department of Homeland Security said Tuesday it was ending a policy that restricted ICE agents’ ability to arrest undocumented people at or near so-called sensitive locations, including houses of worship, schools and hospitals.  Julia Ainsley and Didi Martinez of NBC News contributed to this report.