The federal immigration boss’ threat to flood sanctuary cities with agents is being blasted by Somerville Mayor Joseph A. Curtatone, who called the threatened surge a waste of resources — while Mayor Martin J. Walsh says he’ll “stand strong” with immigrants.

Curtatone told the Herald his sanctuary city always cooperates with Immigration and Customs Enforcement when it comes to violent criminals.

“ICE has no need to step up activity here unless they intend to break President Trump’s original promise, as he put it, to only target ‘bad hombres,’ ” Curtatone said. “If he sends ICE here, it will clearly be because he’s gone back on his word and is now wasting precious resources going after moms, dads and grandmas instead.”

Curtatone called for an “honest conversation” about immigration — including local police on what works in neighborhoods.

“Terrorizing immigrants isn’t on that list,” Curtatone said.

Walsh said in a statement, “I continue to stand strong with our immigrant community and make them feel welcome here in Boston.”

The tough talk on sanctuary cities came last week from ICE acting Director Thomas Homan, who said he wants to make it clear to pols and immigrants alike that “ICE is open for business.”

Homan told the Washington Examiner he’s been given the approval to hire 10,000 more agents, in part to flood large sanctuary cities like Chicago, Philadelphia, New York and San Francisco.

“In the America I grew up in, cities didn’t shield people who violated the law,” Homan told the newspaper.

Fears that more ICE agents would set up shop in Massachusetts sanctuary cities have sparked concern from immigrant groups worried that “there is nobody safe,” said Eva Millona of the Massachusetts Immigrant and Refugee Advocacy Coalition.

“The level of anxiety has escalated tremendously. Kids are afraid to go to school. People are afraid of taking their relatives to hospitals,” Millona said, adding that ICE under Trump has taken to detaining people even if they have not committed any criminal offenses.

“It is concerning because under the Obama administration we saw (an) increase in deportation, but at least there were priorities, criminals going first — but now there is nobody safe, regardless of a person having a conviction or not,” Millona said.

Joshua Goldstein, a Boston immigration attorney, called current immigration enforcement “a radical departure from the way things have been done.”

“I think there’s already outrage in immigrant communities and throughout Massachusetts,” Goldstein said.

But Jessica Vaughan of the Center for Immigration Studies said forcing agents to make arrests in public, rather than in jail, costs more and exposes the public to more risk.

“When they know someone has been released they have to figure out where this person lives, works, they have to surveil them. They have to figure out how they can make the arrest without endangering people,” Vaughan said.