By LEAH WILLINGHAM

BOSTON (AP) — Immigration and Customs Enforcement Acting Director Todd Lyons on Monday defended the use of masks by his agents and expressed frustration at sanctuary jurisdictions that he said are hindering the detainment of immigrants who are in the country illegally.

Lyons said his agents wear masks because they and their families have been doxxed and “targeted” with death threats.

“I’m sorry if people are offended by them wearing masks, but I’m not going to let my officers and agents go out there and put their lives on the line, their family on the line because people don’t like what immigration enforcement is,” he said.

Lyons made the comments during a press conference at the Boston federal courthouse to announce the completion of a May operation in which nearly 1,500 immigrants were taken into custody across Massachusetts. He was leaving the room when a reporter asked him about the masks. He turned around and returned to the podium to answer it.

“Is that the issue here that we’re just upset about the masks?” he asked the room of journalists. “Or is anyone upset about the fact that ICE officers’ families were labeled terrorists?”

As part of last month’s operation, authorities in Massachusetts detained 1,461 immigrants living in Boston, Worcester, Springfield, Lowell, Lawrence, Nantucket, Martha’s Vineyard and other communities. ICE said 790 of those immigrants had criminal histories, including the crime of reentering the U.S. after deportation, and that 277 had previously been ordered to be removed from the country by a federal immigration judge.

Lyons, who is from Boston, said these operations wouldn’t be necessary if “sanctuary cities would change their policy.” There’s no legal definition for sanctuary city policies, but they generally limit cooperation by local law enforcement with federal immigration officers. Courts have repeatedly upheld the legality of sanctuary laws.

Last week, the Department of Homeland Security published a widely anticipated list of “ sanctuary jurisdictions ” on its website, only to receive widespread criticism for including localities that have actively supported the Trump administration’s hard-line immigration policies.

As of Monday, there was a “Page Not Found” error message in its place.

During a March congressional hearing, Boston Mayor Michelle Wu and other Democratic mayors defended sanctuary city policies. Brandon Johnson of Chicago said “mischaracterizations and fearmongering” were obscuring the fact that crime in Chicago is trending down.

“This federal administration is making hard-working, taxpaying, God-fearing residents afraid to live their lives,” Wu said.

During Monday’s press conference, a poster board with mug shots of unnamed immigrants was displayed. A full list of those arrested was not made available, nor was information about the crimes specific individuals are accused of committing.

Lyons called them “dangerous criminals” who are “terrorizing family, friends and our neighbors.”

White House Deputy Chief of Staff Stephen Miller, the key driver of immigration policy in the Trump administration, has said that the administration is setting a goal of 3,000 arrests by ICE each day and that the number could go higher.

Lyons said during an interview with Fox & Friends on Sunday that the agency was averaging about 1,600 arrests per day. He said they can and will do more. That marks an increase from previous ICE arrest data that showed that the agency arrested 78,155 people between Jan. 20 and May 19 — an average of 656 arrests per day.

Lyons heads an agency at the center of Trump’s mass deportations agenda. Just last week, the agency underwent its second major reorganization since Trump took office, as the head of the Enforcement and Removal Operations section of ICE retired and the head of ICE’s Homeland Security Investigations section transitioned to another role.

AP journalist Rebecca Santana contributed to this report from Washington.