More ICE agents are wearing masks. Law enforcement experts say that could be dangerous.

Several of the federal agents who arrested city comptroller and mayoral candidate Brad Lander at a Lower Manhattan immigration court Tuesday were wearing face coverings — a practice that's become increasingly common by federal law enforcement officers across the country.

Masked federal agents took former Columbia University student Mohsen Mahdawi into custody in April, according to video of the arrest. Masked federal agents have also been arresting undocumented immigrants in Massachusetts, and a California lawmaker has proposed banning them.

Critics and former federal law enforcement officials said the tactic is new — and potentially dangerous for agents carrying out the raids and the general public. Being anonymous can help officers dodge accountability and oversight.

“It's completely improper. And again one has to assume they're hiding something or they're hiding misbehavior because otherwise why would they be wearing masks and hiding their identities,” Rep. Jerrold Nadler, a New York Democrat, told reporters Wednesday after viewing masked agents inside a federal building.

The debate over masking has been a flashpoint across the political spectrum, with the Trump administration claiming masked protesters are a threat to safety and order.

A Department of Homeland Security spokesperson said in a statement that agents clearly identify themselves as police, although videos and detainee accounts indicate they do not in some cases.

The spokesperson, did not respond when asked for their name, said agents wear masks to protect themselves from being targeted by "known and suspected terrorist sympathizers.”

The statement went on to criticize "the media" for asking questions about the mask policy and alluded to "terrorist sympathizers on U.S. college campuses" who wear masks and "relish the killing of Americans and Jews."

Agents who detained Lander on Tuesday stopped him in the hallway of a federal building outside immigration court, as he tried to escort a man from the courtroom and requested a copy of a judicial warrant.

“The extent which officers seem to be appearing without not only uniforms, but any sort of visible indicator that they are law-enforcement, and the two of those factors put together, seems to create a lot of danger and risk of people misunderstanding the legitimacy of the law enforcement authority that the officers are exercising,” said Scott Shuchart, a former assistant director at ICE during former President Joe Biden’s administration.

“One of the things that really struck me in the clip that I saw of the Lander arrest is how would somebody in that situation even know that they were interacting with law enforcement,” he added.

He also said if someone wants to get in touch with, or raise a concern about an officer later, it is difficult if they don’t know what they look like, and don’t have a name or badge number.

Jason Wojdylo, a former chief inspector at the U.S. Marshals Service, added that it was uncommon for federal officers to be masked or otherwise unidentifiable — unless they were working undercover.

“That increases the risk level,” Wojdylo said. “It causes people, understandably, to rebel.”

In New York, Mayor Eric Adams has called for a ban on protesters wearing masks.

“When you see people at a protest like that, with masks on, some had gas masks on, it just emboldened them to do bad behavior,” Adams said in an interview with NY1.

Critics of Adams’ proposed mask crackdown said limiting masking specifically at protests would be unconstitutional.

“They have a right to protest anonymously, and that's true whether or not we agree with the message of the particular protest,” said Allie Bohm, the senior policy counsel at the New York Civil Liberties Union.